atomic structure 3.1. october 1, 2015 objective: explain dalton’s atomic theory and describe why...

Atomic StructureAtomic Structure

3.1

October 1, 2015October 1, 2015

Objective: Explain Dalton’s atomic theory and describe why it was more successful than Democritus’ atomic theory.

Do Now: Name the 3 subatomic particles found in an atom (the 3 parts of an atom).

Objective: Explain Dalton’s atomic theory and describe why it was more successful than Democritus’ atomic theory.

Do Now: Name the 3 subatomic particles found in an atom (the 3 parts of an atom).

Atomic HistoryAtomic History

•In 400 BC a Greek Philosopher, Democritus suggested the universe was made of invisible units--atoms.

•In 400 BC a Greek Philosopher, Democritus suggested the universe was made of invisible units--atoms.

1800’s John Dalton’s Theory

(Still Accepted)

1800’s John Dalton’s Theory

(Still Accepted)

1.Every element is made of tiny, unique particles called atoms

2.Atoms of different elements can join to form molecules.

1.Every element is made of tiny, unique particles called atoms

2.Atoms of different elements can join to form molecules.

John Dalton’s Theory- DisprovedJohn Dalton’s Theory- Disproved

3.Atoms are the smallest particles and cannot be subdivided.

4.Atoms of the same element are exactly alike in mass

3.Atoms are the smallest particles and cannot be subdivided.

4.Atoms of the same element are exactly alike in mass

JJ ThomsonJJ Thomson

Credited with discovering negative charged particles called electrons.

Credited with discovering negative charged particles called electrons.

https://www.youtube.com/watch?v=2xKZRpAsWL8

https://www.youtube.com/watch?v=O9Goyscbazk

RutherfordRutherford

Credited with discovering nucleus.

and atoms are mostly empty space.

Credited with discovering nucleus.

and atoms are mostly empty space.

https://www.youtube.com/watch?v=5pZj0u_XMbc

http://micro.magnet.fsu.edu/electromag/java/rutherford/

Further Research FindingFurther Research Finding

Later on, the discovery of protons and neutrons were discovered in the nucleus.

And it was later concluded that all atoms are neutral in charge.

The number of protons and electrons in any atom are always equal.

Later on, the discovery of protons and neutrons were discovered in the nucleus.

And it was later concluded that all atoms are neutral in charge.

The number of protons and electrons in any atom are always equal.

Niels BohrNiels BohrSuggested that electrons move around atoms in set paths around the nucleus.

He said each path is an energy level

Suggested that electrons move around atoms in set paths around the nucleus.

He said each path is an energy level

See visual aid in Ch4 online txtbk

Today’s TheoryToday’s Theory

It is impossible to pinpoint an electron’s exact position due to its tremendous speed.

Electrons do not move around in definite paths.

It is impossible to pinpoint an electron’s exact position due to its tremendous speed.

Electrons do not move around in definite paths.

Today’s TheoryToday’s Theory

Electrons are found in orbitals within energy levels. (s, p, d, and f )a region in an atom where there is a high probability of finding electrons.

Electrons are found in orbitals within energy levels. (s, p, d, and f )a region in an atom where there is a high probability of finding electrons.

Today’s TheoryToday’s TheoryElectrons are now viewed as waves vibrating on a string rather than simple particles.

Wave-Particle Duality Theory

Electrons are now viewed as waves vibrating on a string rather than simple particles.

Wave-Particle Duality Theory

What are atoms?What are atoms?

The smallest part of an element that still has the element’s properties.

The smallest part of an element that still has the element’s properties.

Parts of an atomParts of an atom

NucleusProtonNeutron

Electron

NucleusProtonNeutron

Electron

Subatomic particles

NucleusNucleus•center of an atom

•positively charged

•makes up 99.9% of the atom’s mass

•contains protons and neutrons

•center of an atom

•positively charged

•makes up 99.9% of the atom’s mass

•contains protons and neutrons

ProtonsProtonsCharge (+)

Mass is equal to 1 atomic mass unit (amu)

Found in the nucleus

Identifies the element/atom

Charge (+)

Mass is equal to 1 atomic mass unit (amu)

Found in the nucleus

Identifies the element/atom

NeutronsNeutronsCharge (0) – neutral

Mass is equal to 1amu

Found in the nucleus

Helps determine mass

Charge (0) – neutral

Mass is equal to 1amu

Found in the nucleus

Helps determine mass

ElectronsElectrons•Charge is negative (-)

•Mass is equal to 0 amu

•Found outside the nucleus, in the electron cloud

•Charge is negative (-)

•Mass is equal to 0 amu

•Found outside the nucleus, in the electron cloud

Energy levels Energy levels

1st level holds up to 2 e- 2nd level holds up to 8 e- 3rd level holds up to 8 or 18 e-

4th level holds up to 8, 18, or 32 e-

Outer Level holds up to 8 e-(called valence electrons)

1st level holds up to 2 e- 2nd level holds up to 8 e- 3rd level holds up to 8 or 18 e-

4th level holds up to 8, 18, or 32 e-

Outer Level holds up to 8 e-(called valence electrons)

Valence ElectronValence Electron

The number of electrons in the outermost electron shell.

Most important

The number of electrons in the outermost electron shell.

Most important

Oct 6, 2014Oct 6, 2014

Objective: Quantify atoms and ions based on subatomic particles

Do Now: How many valence e- will the following elements have? (Draw out your energy orbitals with the “nucleus” in the center to show work) Carbon

Na

Hydrogen

Chlorine

Objective: Quantify atoms and ions based on subatomic particles

Do Now: How many valence e- will the following elements have? (Draw out your energy orbitals with the “nucleus” in the center to show work) Carbon

Na

Hydrogen

Chlorine

A Guided Tour of the Periodic Table

A Guided Tour of the Periodic Table

3.23.2 https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=meet%20the%20elements Meet the Elements

Periodic Law Periodic Law

•Properties of elements tend to change in a regular pattern when elements are arranged in order of increasing atomic number.

•Properties of elements tend to change in a regular pattern when elements are arranged in order of increasing atomic number.

Periodic Law Periodic Law

Periodic Table is set up by increasing atomic number.

Atomic Number is the # of protons in the atom.

Periodic Table is set up by increasing atomic number.

Atomic Number is the # of protons in the atom.

Average Atomic

Mass

Atomic Number Atomic Number•tells you number of protons•Never Changes for an atom.•Appears as a whole # on the periodic table.•No two elements can have same atomic #.

•tells you number of protons•Never Changes for an atom.•Appears as a whole # on the periodic table.•No two elements can have same atomic #.

Atomic NumberAtomic Number

# of protons

Atomic Number

Mass Number Mass Number

The mass of an atomTotal number of protons plus

neutrons in the nucleus of a single atom.

Atoms of the same element won’t always have the same mass number

The mass of an atomTotal number of protons plus

neutrons in the nucleus of a single atom.

Atoms of the same element won’t always have the same mass number

Mass NumberMass Number

# of protons

# ofneutrons Mass

#

Isotopes Isotopes

•Any atoms having the same number of protons but different number of neutrons.•So they also have different mass numbers.

•Any atoms having the same number of protons but different number of neutrons.•So they also have different mass numbers.

Average Atomic MassAverage Atomic Mass

Average mass of all known isotopes for an element

Found on the periodic table as a number with a decimal

Average mass of all known isotopes for an element

Found on the periodic table as a number with a decimal

Atom’s Charge Atom’s Charge

•They are neutral.

•All atoms have the same number of protons and electrons.

•Charges cancel each other out.

•They are neutral.

•All atoms have the same number of protons and electrons.

•Charges cancel each other out.

Ions Ions

Charged particles. Form when atoms lose or gain

electrons.They do this so the ions have a

full outer shellTwo Types.

Charged particles. Form when atoms lose or gain

electrons.They do this so the ions have a

full outer shellTwo Types.

Cations Cations

•Positively charged ions.

•Form when atoms lose electrons.

•Metals

•Left side of table

•Positively charged ions.

•Form when atoms lose electrons.

•Metals

•Left side of table

Cations Cations

# of protons greater than # of electrons

More (+) than (-)

# of protons greater than # of electrons

More (+) than (-)

Na AtomNa+ Cation

Anions Anions

•Negatively charged ions. •Form when atoms gain electrons.•Nonmetals•Right side of table

•Negatively charged ions. •Form when atoms gain electrons.•Nonmetals•Right side of table

Anions Anions

# of protons less than # of electrons

More (-) than (+)

# of protons less than # of electrons

More (-) than (+)

Cl atom

Cl- Anion

Quantifying atoms or ionsQuantifying atoms or ions

+1 Protons = 3

Neutrons = 7-3 = 4

Electrons = 3

Electrons = 3 -1 = 2

Families of Elements

Families of Elements

3.33.3

Periodic TablePeriodic TablePeriods

-a horizontal row of elements.

-Tells you the electrons energy level.

Periods

-a horizontal row of elements.

-Tells you the electrons energy level.

Periodic TablePeriodic TableGroups (families) -a vertical column of elements.

-Tells us the # of valence electrons and the elements’ chemical properties.

Groups (families) -a vertical column of elements.

-Tells us the # of valence electrons and the elements’ chemical properties.

Types of ElementsTypes of Elements

1.Metals

2.Nonmetals

3.Semiconductors/metalloid

1.Metals

2.Nonmetals

3.Semiconductors/metalloid

Transition Metals

Alkaline Earth Metals

Alkali Metals

Metalloids

Other Metals

Non Metals

Halogens

Nobel Gases

Inner Transition Metals

Alkali Metals Group 1Alkali Metals Group 1Most reactive metals one valence e-Found as compounds (salts) and not

elements due to reactivity.As elements they are soft metals and

good conductors.

Most reactive metals one valence e-Found as compounds (salts) and not

elements due to reactivity.As elements they are soft metals and

good conductors.

fun

Alkaline-earth MetalsGroup 2

Alkaline-earth MetalsGroup 2

Less reactive than AlkaliThey are also more commonly found as compounds

2 most common are Ca and Mg.

Less reactive than AlkaliThey are also more commonly found as compounds

2 most common are Ca and Mg.

Transition Metals Groups 3-12

Transition Metals Groups 3-12

Less reactive than groups 1 and 2

Good conductors

Less reactive than groups 1 and 2

Good conductors

Transition MetalsTransition Metals

All solids with the exception of mercury

Valuable metals (Ag, Au, Pt, Cu, Ni, Fe, Co)

All solids with the exception of mercury

Valuable metals (Ag, Au, Pt, Cu, Ni, Fe, Co)

Non MetalsNon Metals

Are not able to conduct electricity or heat very well.

Found in groups 13-18, with the exception of hydrogen

Are not able to conduct electricity or heat very well.

Found in groups 13-18, with the exception of hydrogen

CarbonCarbon

Found as an element (coal, diamond, graphite)

Found in millions of different compounds

Called Organic Compounds

Found as an element (coal, diamond, graphite)

Found in millions of different compounds

Called Organic Compounds

HYDROGENHYDROGENIt is a gas/nonmetalA very explosive gas.It is located in group one

because it has one valence electron

http://www.youtube.com/watch?v=KLzY88uHFn0

It is a gas/nonmetalA very explosive gas.It is located in group one

because it has one valence electron

http://www.youtube.com/watch?v=KLzY88uHFn0

Oxygen and NitrogenOxygen and Nitrogen

Oxygen is the most common element found on Earth

Nitrogen most common gas found in the atmosphere

Oxygen is the most common element found on Earth

Nitrogen most common gas found in the atmosphere

Halogens Group 17

Halogens Group 17

Most reactive nonmetalsForm salts with group 1Used to kill bacteriaBromine only liquid nonmetal

Most reactive nonmetalsForm salts with group 1Used to kill bacteriaBromine only liquid nonmetal

Noble Gases Group 18Noble Gases Group 18Stable and not reactive. (inert)

Don’t form compounds.They have a full valence shell.

Stable and not reactive. (inert)

Don’t form compounds.They have a full valence shell.

Metalloids (Semiconductors)

Metalloids (Semiconductors)

7 elements on the step

Properties of both metals and non-metals.

Silicon the most familiar (computer chips)

7 elements on the step

Properties of both metals and non-metals.

Silicon the most familiar (computer chips)

Inner Transition MetalsInner Transition MetalsTwo rows at the bottomSome are Radioactive ex. Uranium

93 and greater are all manmade

Two rows at the bottomSome are Radioactive ex. Uranium

93 and greater are all manmade