Chapter 2 Atoms Molecules and Ions

1

2

bull Democritus (460-370bc)bull -two possibilities for matter bull (1) matter is continuous

bull Subdivided indefinitely ndash no basic particle

bull (2) matter is discontinuousbull Eventually subdivide to a basic particle

bull can not be broken down furtherbull a = not tomos = cut atomos = not able to

cut

The Early History of Chemistry-Ancient GreeksThe Early History of Chemistry-Ancient Greeks

3

AlchemistsAlchemistsbull Before 16th Century

ndash Alchemy Attempts (scientific or otherwise) to change cheap metals into gold

bull Psuedo-chemistsbull Attempted to make

bull Gold from other metalsbull Elixir of Life ndash panacea

bull everlasting life

bull Created gunpowder glass ceramics medicine

bull metallurgy ndash extraction of metals from orebull Alloys ndash brass bronze steelhellip

4

Law of Conservation of MassLaw of Conservation of Masso Mass is neither created nor

destroyed in chemical or physical changes

o mass of reactants must equal mass of products

o ldquowhat you start with you must end withrdquo

bull Joseph Proust

ndashlaw of definite proportionsbull a given compound always contains the

same proportion of elements by massbull carbon tetrachloride is always 1 g of

carbon per 12 grams chlorine

5

2

bull Democritus (460-370bc)bull -two possibilities for matter bull (1) matter is continuous

bull Subdivided indefinitely ndash no basic particle

bull (2) matter is discontinuousbull Eventually subdivide to a basic particle

bull can not be broken down furtherbull a = not tomos = cut atomos = not able to

cut

The Early History of Chemistry-Ancient GreeksThe Early History of Chemistry-Ancient Greeks

3

AlchemistsAlchemistsbull Before 16th Century

ndash Alchemy Attempts (scientific or otherwise) to change cheap metals into gold

bull Psuedo-chemistsbull Attempted to make

bull Gold from other metalsbull Elixir of Life ndash panacea

bull everlasting life

bull Created gunpowder glass ceramics medicine

bull metallurgy ndash extraction of metals from orebull Alloys ndash brass bronze steelhellip

4

Law of Conservation of MassLaw of Conservation of Masso Mass is neither created nor

destroyed in chemical or physical changes

o mass of reactants must equal mass of products

o ldquowhat you start with you must end withrdquo

bull Joseph Proust

ndashlaw of definite proportionsbull a given compound always contains the

same proportion of elements by massbull carbon tetrachloride is always 1 g of

carbon per 12 grams chlorine

5

3

AlchemistsAlchemistsbull Before 16th Century

ndash Alchemy Attempts (scientific or otherwise) to change cheap metals into gold

bull Psuedo-chemistsbull Attempted to make

bull Gold from other metalsbull Elixir of Life ndash panacea

bull everlasting life

bull Created gunpowder glass ceramics medicine

bull metallurgy ndash extraction of metals from orebull Alloys ndash brass bronze steelhellip

4

Law of Conservation of MassLaw of Conservation of Masso Mass is neither created nor

destroyed in chemical or physical changes

o mass of reactants must equal mass of products

o ldquowhat you start with you must end withrdquo

bull Joseph Proust

ndashlaw of definite proportionsbull a given compound always contains the

same proportion of elements by massbull carbon tetrachloride is always 1 g of

carbon per 12 grams chlorine

5

4

Law of Conservation of MassLaw of Conservation of Masso Mass is neither created nor

destroyed in chemical or physical changes

o mass of reactants must equal mass of products

o ldquowhat you start with you must end withrdquo

bull Joseph Proust

ndashlaw of definite proportionsbull a given compound always contains the

same proportion of elements by massbull carbon tetrachloride is always 1 g of

carbon per 12 grams chlorine

5

bull Joseph Proust

ndashlaw of definite proportionsbull a given compound always contains the

same proportion of elements by massbull carbon tetrachloride is always 1 g of

carbon per 12 grams chlorine

5

6

19th Century19th CenturyJohn Dalton (1766-1844)

bull Work with weather lead him to study gases

bull Volumes of gases combined in simple whole ratios by weight

bull Some underlying factor causing this ratio

Law of Multiple Proportions

o When two elements form a series of compounds the ratios of the masses of the second element that combine with the first element can always be reduced to small whole numberso The ratio of the masses in H2O = 18o The ratio of the masses in H2O2 = 116

o small whole number of 2

7

Daltonrsquos Atomic Theory (1808)Daltonrsquos Atomic Theory (1808)

postulates of Daltonrsquos atomic theory1) Each element is made up of tiny

particles called atoms Atoms are indestructable

2) The atoms of a given element are identical the atoms of different elements are different in some fundamental way or ways

8

Daltonrsquos Atomic TheoryDaltonrsquos Atomic Theory

3) Chemical compounds are formed when atoms combine with each other

4) Chemical reactions involve reorganization of the atoms in whole number ratios - atoms themselves are not changed in a chemical reaction

9

Early Experiments to characterize the Atom

Early Experiments to characterize the Atom

bull J J Thomson - postulated the existence of electrons using cathode ray tubes

bull Henri Becquerelndash discovered some elements released

particles and NRG

bull Pierre and Marie Curiendash radioactivity ndash spontaneous release of

particles and NRG from matterndash isolated uranium from orendash discovered Po and Ra

10

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

7

Daltonrsquos Atomic Theory (1808)Daltonrsquos Atomic Theory (1808)

postulates of Daltonrsquos atomic theory1) Each element is made up of tiny

particles called atoms Atoms are indestructable

2) The atoms of a given element are identical the atoms of different elements are different in some fundamental way or ways

8

Daltonrsquos Atomic TheoryDaltonrsquos Atomic Theory

3) Chemical compounds are formed when atoms combine with each other

4) Chemical reactions involve reorganization of the atoms in whole number ratios - atoms themselves are not changed in a chemical reaction

9

Early Experiments to characterize the Atom

Early Experiments to characterize the Atom

bull J J Thomson - postulated the existence of electrons using cathode ray tubes

bull Henri Becquerelndash discovered some elements released

particles and NRG

bull Pierre and Marie Curiendash radioactivity ndash spontaneous release of

particles and NRG from matterndash isolated uranium from orendash discovered Po and Ra

10

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

8

Daltonrsquos Atomic TheoryDaltonrsquos Atomic Theory

3) Chemical compounds are formed when atoms combine with each other

4) Chemical reactions involve reorganization of the atoms in whole number ratios - atoms themselves are not changed in a chemical reaction

9

Early Experiments to characterize the Atom

Early Experiments to characterize the Atom

bull J J Thomson - postulated the existence of electrons using cathode ray tubes

bull Henri Becquerelndash discovered some elements released

particles and NRG

bull Pierre and Marie Curiendash radioactivity ndash spontaneous release of

particles and NRG from matterndash isolated uranium from orendash discovered Po and Ra

10

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

9

Early Experiments to characterize the Atom

Early Experiments to characterize the Atom

bull J J Thomson - postulated the existence of electrons using cathode ray tubes

bull Henri Becquerelndash discovered some elements released

particles and NRG

bull Pierre and Marie Curiendash radioactivity ndash spontaneous release of

particles and NRG from matterndash isolated uranium from orendash discovered Po and Ra

10

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

bull Henri Becquerelndash discovered some elements released

particles and NRG

bull Pierre and Marie Curiendash radioactivity ndash spontaneous release of

particles and NRG from matterndash isolated uranium from orendash discovered Po and Ra

10

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

bull Ernest Rutherford ndash names particles that are released

from atoms alpha(α) and beta(β)ndash explained the nuclear atom

containing a dense nucleus with electrons traveling around the nucleus at a large distance

11

12

The Modern View of Atomic StructureThe Modern View of Atomic Structure electrons(e-) point-like particles

- virtually no mass- e- cloud gives atom volume

protons(p+) found in the nucleus- positive charge equalopposite

e-

- mass particle

neutrons(no) found in the nucleus- no charge

- virtually same mass as a proton

13

The Mass and Change of the Electron Proton and NeutronThe Mass and Change of the

Electron Proton and Neutron

Particle Mass (kg) Charge

Electron 911 10 31 1

Proton 167 10 27 1+

Neutron 167 10 27 0

14

The Chemistsrsquo Shorthand Atomic Symbols

The Chemistsrsquo Shorthand Atomic Symbols

K Element Symbol39

19

Mass number

Atomic number

K-39

13

The Mass and Change of the Electron Proton and NeutronThe Mass and Change of the

Electron Proton and Neutron

Particle Mass (kg) Charge

Electron 911 10 31 1

Proton 167 10 27 1+

Neutron 167 10 27 0

14

The Chemistsrsquo Shorthand Atomic Symbols

The Chemistsrsquo Shorthand Atomic Symbols

K Element Symbol39

19

Mass number

Atomic number

K-39

14

The Chemistsrsquo Shorthand Atomic Symbols

The Chemistsrsquo Shorthand Atomic Symbols

K Element Symbol39

19

Mass number

Atomic number

K-39

bull Max Planckndash black body radiationndash NRG released in discrete units

quantandash Planck equation E = hυ

bull E = NRGbull h = Planckrsquos Constant(6626 x 10-34 J s)bull υ = frequency

15

video

bull Albert Einsteinndash determines that light if it is related to

Planckrsquos quanta must be composed of particles(photons)

ndash photoelectric effect ndash electrons are ejected from the surface of metals when light is shined on thembull waves canrsquot account for the electrons being

ejected but particles canndash light is a wave and also consists of

particles

16

17

71 Electromagnetic Radiationbull Radiant energy that exhibits

wavelength-like behavior and travels through space at the speed of light in a vacuumndash lightndash infraredndash microwavesndash ultraviolet(UV rays)

18

bull Waves have 3 primary characteristics1Wavelength distance between two

peaks in a wave

2 Frequency number of waves per second that pass a given point in space

3Speed speed of light is 29979 108 ms

c = λνspeed of light(c) = wavelength(λ) x

frequency(ν)c = 29979 x 108 ms

ndash constant in a vacuum

λ ndash measured in distance(m nm cm)ν ndash measured in 1s Hertz(Hz) = cycless

λ asymp 1ν

19

bull Niels Bohr

20

bull Student of Rutherfordbull Studied NRG released from atoms

bull Determined NRG given off in discrete amounts(quanta)

bull Theorized NRG was directly related to movement of electrons from higher NRG states to lower NRG statesbull Discrete energy levelsbull Basis of quantum mechanical model

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

17

71 Electromagnetic Radiationbull Radiant energy that exhibits

wavelength-like behavior and travels through space at the speed of light in a vacuumndash lightndash infraredndash microwavesndash ultraviolet(UV rays)

18

bull Waves have 3 primary characteristics1Wavelength distance between two

peaks in a wave

2 Frequency number of waves per second that pass a given point in space

3Speed speed of light is 29979 108 ms

c = λνspeed of light(c) = wavelength(λ) x

frequency(ν)c = 29979 x 108 ms

ndash constant in a vacuum

λ ndash measured in distance(m nm cm)ν ndash measured in 1s Hertz(Hz) = cycless

λ asymp 1ν

19

bull Niels Bohr

20

bull Student of Rutherfordbull Studied NRG released from atoms

bull Determined NRG given off in discrete amounts(quanta)

bull Theorized NRG was directly related to movement of electrons from higher NRG states to lower NRG statesbull Discrete energy levelsbull Basis of quantum mechanical model

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

18

bull Waves have 3 primary characteristics1Wavelength distance between two

peaks in a wave

2 Frequency number of waves per second that pass a given point in space

3Speed speed of light is 29979 108 ms

c = λνspeed of light(c) = wavelength(λ) x

frequency(ν)c = 29979 x 108 ms

ndash constant in a vacuum

λ ndash measured in distance(m nm cm)ν ndash measured in 1s Hertz(Hz) = cycless

λ asymp 1ν

19

bull Niels Bohr

20

bull Student of Rutherfordbull Studied NRG released from atoms

bull Determined NRG given off in discrete amounts(quanta)

bull Theorized NRG was directly related to movement of electrons from higher NRG states to lower NRG statesbull Discrete energy levelsbull Basis of quantum mechanical model

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

c = λνspeed of light(c) = wavelength(λ) x

frequency(ν)c = 29979 x 108 ms

ndash constant in a vacuum

λ ndash measured in distance(m nm cm)ν ndash measured in 1s Hertz(Hz) = cycless

λ asymp 1ν

19

bull Niels Bohr

20

bull Student of Rutherfordbull Studied NRG released from atoms

bull Determined NRG given off in discrete amounts(quanta)

bull Theorized NRG was directly related to movement of electrons from higher NRG states to lower NRG statesbull Discrete energy levelsbull Basis of quantum mechanical model

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

bull Niels Bohr

20

bull Student of Rutherfordbull Studied NRG released from atoms

bull Determined NRG given off in discrete amounts(quanta)

bull Theorized NRG was directly related to movement of electrons from higher NRG states to lower NRG statesbull Discrete energy levelsbull Basis of quantum mechanical model

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

21

bull Bohr Model of atombull Planetary model

bull Electrons revolve around nucleus like planets around the sun

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

22

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

23

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

Bohr Model of Atom

24

bull Only works for hydrogenbull No other spectral lines match energy of

the electronsbull Doesnrsquot explain why electrons donrsquot fall in

to nucleusbull Electrons give off energy and move toward

nucleus yet they never fall in to the nucleusbull If e- fell in to the nucleus matter would not exist

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

25

Energy and Massbull Energy has mass

bull E = mc2

bull E = energybull m = massbull c = speed of light

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

26

Energy and Mass

Ehc

photon =

mhcphoton =

(Hence the dual nature of light)

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

Louis de Broglie

27

bull Mathematically derived equation that proved electron has wave-like propertiesbull Electron is a particle (classical physics)

bull Behaves as particles shouldbull Affected by forcesbull Has mass

bull Electron is a wave (quantum physics)bull Has wave properties

bull Double slit experimentbull Wavelength and frequency can be measured

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

28

Wave-Particle Duality theory

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

29

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

30

Wave-Particle Duality theorybull Waves exhibit particle-like

propertiesbull Photonsbull Photoelectric effect

bull Particles exhibit wave-like propertiesbull Frequency and wavelength of

particlesbull Dual slit experiment

video

31

Quantum Mechanical Model

32

Heisenberg Uncertainty Principle

bull The exact position and momentumspeed of a particle cannot be simultaneously knownbull You can never know where a particle is

located and how fast the particle is moving at the same time

bull the more precise the measurement of a particles position the more uncertainty of the particles momentum and vice versabull not due to how fast or how small just a

fact of life

33

Heisenberg Uncertainty Principlebull Large particles have little uncertainty

bull Baseballbull Due to the baseballs large mass the amount

of uncertainty of where the ball is or how fast the ball is traveling is very small(not measurable)

bull Small particles have high uncertaintybull Electron

bull Due to the electrons small mass the amount of uncertainty of where the electron is or how fast the electron is traveling is very large(canrsquot know position if momentum is known canrsquot know momentum if position is known)

34

Quantum Mechanical Modelbull Visual examplebull Bees around a hive

bull Bees are electrons bull Around hive but in no determinate path(electrons)bull Collectively bees occupy a space around the hive(electron

cloud)bull Specific location and speed of each bee is ldquoimpossiblerdquo to

determinebull However the bees energy(wavelength and frequency)

could be measured

video

32

Heisenberg Uncertainty Principle

bull The exact position and momentumspeed of a particle cannot be simultaneously knownbull You can never know where a particle is

located and how fast the particle is moving at the same time

bull the more precise the measurement of a particles position the more uncertainty of the particles momentum and vice versabull not due to how fast or how small just a

fact of life

33

Heisenberg Uncertainty Principlebull Large particles have little uncertainty

bull Baseballbull Due to the baseballs large mass the amount

of uncertainty of where the ball is or how fast the ball is traveling is very small(not measurable)

bull Small particles have high uncertaintybull Electron

bull Due to the electrons small mass the amount of uncertainty of where the electron is or how fast the electron is traveling is very large(canrsquot know position if momentum is known canrsquot know momentum if position is known)

34

Quantum Mechanical Modelbull Visual examplebull Bees around a hive

bull Bees are electrons bull Around hive but in no determinate path(electrons)bull Collectively bees occupy a space around the hive(electron

cloud)bull Specific location and speed of each bee is ldquoimpossiblerdquo to

determinebull However the bees energy(wavelength and frequency)

could be measured

video

33

Heisenberg Uncertainty Principlebull Large particles have little uncertainty

bull Baseballbull Due to the baseballs large mass the amount

of uncertainty of where the ball is or how fast the ball is traveling is very small(not measurable)

bull Small particles have high uncertaintybull Electron

bull Due to the electrons small mass the amount of uncertainty of where the electron is or how fast the electron is traveling is very large(canrsquot know position if momentum is known canrsquot know momentum if position is known)

34

Quantum Mechanical Modelbull Visual examplebull Bees around a hive

bull Bees are electrons bull Around hive but in no determinate path(electrons)bull Collectively bees occupy a space around the hive(electron

cloud)bull Specific location and speed of each bee is ldquoimpossiblerdquo to

determinebull However the bees energy(wavelength and frequency)

could be measured

video

34

Quantum Mechanical Modelbull Visual examplebull Bees around a hive

bull Bees are electrons bull Around hive but in no determinate path(electrons)bull Collectively bees occupy a space around the hive(electron

cloud)bull Specific location and speed of each bee is ldquoimpossiblerdquo to

determinebull However the bees energy(wavelength and frequency)

could be measured

video

35

Quantum Mechanical Modelbull currently accepted model of atombull Most probable location of electrons

described with quantum numbersbull Canrsquot know exact position or path

bull Predict most probable location of locating an electron in a specific region around the nucleusbull Similar to predicting Mr Andresenrsquos location in

the school at any given moment

36

Quantum Numbersbull Quantum numbers describe most probable

location of electrons around the nucleus(3-D model)

1Principal Quantum numberbull Denotes distance electrons are from the

nucleusbull Similar to the number of floors in a

buildingbull NRG levels

bull Whole numbers(n = 1 2 3 )bull 1st nrg level is closest to nucleusbull 7th nrg level is farthest from nucleus

37

Quantum Numbers

2Orbital(angular momentum) Quantum numberbull Indicates the shape of where the electron is

most probably located within the NRG level bull Similar to the shape of a room in a building

bull Denoted by letters s p d f (g h i jhellip)bull s-orbital smallest

bull lowest NRG orbitalbull f-orbital largest most complex

bull highest NRG orbital

38

Quantum Numbersbull s-orbital

bull spherical shapedbull only 1 orbitalNRG level

bull p-orbitalbull peanut shaped

bull 3 orbitalsNRG level(starting with 2nd NRG level)

bull d-orbitalbull 4 four leaf clover shaped + weird shape

bull 5 orbitalsNRG level(starting with 3rd NRG level)

bull f-orbitalbull 7 very complex shapes(flower petals)

bull 7 orbitalsNRG level(starting with 4th NRG level)

39

Quantum Numbers

3Magnetic quantum numberbull indicates the position of each orbital in

the nrg level with regard to the three axis(x y z) in spacebull s-orbital only has one position

bull sxyz ndash sphere is positioned on all three axis equally

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

36

Quantum Numbersbull Quantum numbers describe most probable

location of electrons around the nucleus(3-D model)

1Principal Quantum numberbull Denotes distance electrons are from the

nucleusbull Similar to the number of floors in a

buildingbull NRG levels

bull Whole numbers(n = 1 2 3 )bull 1st nrg level is closest to nucleusbull 7th nrg level is farthest from nucleus

37

Quantum Numbers

2Orbital(angular momentum) Quantum numberbull Indicates the shape of where the electron is

most probably located within the NRG level bull Similar to the shape of a room in a building

bull Denoted by letters s p d f (g h i jhellip)bull s-orbital smallest

bull lowest NRG orbitalbull f-orbital largest most complex

bull highest NRG orbital

38

Quantum Numbersbull s-orbital

bull spherical shapedbull only 1 orbitalNRG level

bull p-orbitalbull peanut shaped

bull 3 orbitalsNRG level(starting with 2nd NRG level)

bull d-orbitalbull 4 four leaf clover shaped + weird shape

bull 5 orbitalsNRG level(starting with 3rd NRG level)

bull f-orbitalbull 7 very complex shapes(flower petals)

bull 7 orbitalsNRG level(starting with 4th NRG level)

39

Quantum Numbers

3Magnetic quantum numberbull indicates the position of each orbital in

the nrg level with regard to the three axis(x y z) in spacebull s-orbital only has one position

bull sxyz ndash sphere is positioned on all three axis equally

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

37

Quantum Numbers

2Orbital(angular momentum) Quantum numberbull Indicates the shape of where the electron is

most probably located within the NRG level bull Similar to the shape of a room in a building

bull Denoted by letters s p d f (g h i jhellip)bull s-orbital smallest

bull lowest NRG orbitalbull f-orbital largest most complex

bull highest NRG orbital

38

Quantum Numbersbull s-orbital

bull spherical shapedbull only 1 orbitalNRG level

bull p-orbitalbull peanut shaped

bull 3 orbitalsNRG level(starting with 2nd NRG level)

bull d-orbitalbull 4 four leaf clover shaped + weird shape

bull 5 orbitalsNRG level(starting with 3rd NRG level)

bull f-orbitalbull 7 very complex shapes(flower petals)

bull 7 orbitalsNRG level(starting with 4th NRG level)

39

Quantum Numbers

3Magnetic quantum numberbull indicates the position of each orbital in

the nrg level with regard to the three axis(x y z) in spacebull s-orbital only has one position

bull sxyz ndash sphere is positioned on all three axis equally

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

38

Quantum Numbersbull s-orbital

bull spherical shapedbull only 1 orbitalNRG level

bull p-orbitalbull peanut shaped

bull 3 orbitalsNRG level(starting with 2nd NRG level)

bull d-orbitalbull 4 four leaf clover shaped + weird shape

bull 5 orbitalsNRG level(starting with 3rd NRG level)

bull f-orbitalbull 7 very complex shapes(flower petals)

bull 7 orbitalsNRG level(starting with 4th NRG level)

39

Quantum Numbers

3Magnetic quantum numberbull indicates the position of each orbital in

the nrg level with regard to the three axis(x y z) in spacebull s-orbital only has one position

bull sxyz ndash sphere is positioned on all three axis equally

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

39

Quantum Numbers

3Magnetic quantum numberbull indicates the position of each orbital in

the nrg level with regard to the three axis(x y z) in spacebull s-orbital only has one position

bull sxyz ndash sphere is positioned on all three axis equally

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

40

Quantum Numbers

bull p-orbital has three positionsbull px py pz ndash one peanut shape on each

axis

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

41

Quantum Numbersbull d-orbital has five positions

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

42

Quantum Numbersbull f-orbital has seven positions

bull way to complex for us

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

43

Quantum Numbers4Spin Quantum number

bull indicates the spinmagnetic field orientation of the electronbull according to classical physics a charged

object that is spinning creates a magnetic field

bull electrons have a magnetic field ie they are ldquospinningrdquo

bull denoted with +12 and -12bull also denoted with bull each orbital position can hold a maximum of 2

electrons but they must have opposite spin(Paulirsquos Exclusion Principle)bull s-orbitals = 2 electronsbull p-orbitals = 6 electronsbull d-orbitals = 10 electronsbull f-orbitals = 14 electrons

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

44

Pauli Exclusion Principlebull In a given atom no two

electrons can have the same set of four quantum numbers

bull Therefore an orbital can hold only two electrons and they must have opposite spins

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

45

Aufbau Principle

bull As protons are added one by one to the nucleus to build up the elements electrons are similarly added to these hydrogen-like orbitals

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level

46

Hundrsquos Rule

bull The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of orbitals

bull e- remain unpaired until each orbital is occupied in an NRG level