4.1 atomic theory & bonding
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4.1 VOCABULARYAlkali earth metalsAlkali metalsAnionsAtomic #Atomic numberAtomic TheoryAtoms Bohr diagramCations Chemical ChangeChemical reactionCompound Covalent bonding
MoleculeNeutronNoble gasesNon-MetalNucleusPeriodProtonPure SubstanceStable outer shellSubatomic particleTransition metalsValence electrons
Covalent CompoundElectronsElement Family/GroupHalogensIonic bondingIonic compoundsIonsLewis DiagramMatterMetalMetalloidsMixture
MechanicalSuspensions
Solutions Elements Compounds
No new substances produced
Only a change in state or appearance
New substances produced
Very hard to reverse
= CHEMICAL REACTION
• An atom is the smallest particle of an element that still has the properties of that element
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See pages 168 - 169
ATOMS
50 million atoms, lined up end to end = 1 cm
An atom = proton(s) + neutron(s) + electron(s)
Atoms join together to form compounds
A compound is a pure substance that is composed of two or more atoms combined in a specific way.
Oxygen and hydrogen are atoms/elements; H2O is a compound.
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COMPOUNDS
COMPOUNDS
A chemical change occurs when the arrangement of atoms in compounds changes to form new compounds.
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CHEMICAL CHANGE
Atoms are made up of smaller particles called subatomic particles.
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See page 170
ATOMIC THEORY
• The nucleus is at the center of an atom
• The nucleus is composed of -positive protons and neutral neutrons
• Electrons exist in the space surrounding the nucleus.
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See page 170
ATOMIC THEORY
# of protons = # of electrons in every atomNuclear charge = charge on the nucleus = # of protons
Nuclear charge = Atomic number Atomic number = # of protons = # of electrons
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See page 170
ATOMIC THEORY
INCR
EASI
NG
REAC
TIVI
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ELEMENTSAtomic Number = smaller number
= number of p+ and e-
Atomic Mass = larger number= total of p+ and n0
28 +2 +3
Ni Nickel
58.71
Atomic Number
Atomic Mass
Combining Capacities
Symbol
Name of Element
CALCULATING NUMBER OF SUBATOMIC PARTICLES• Protons = same as atomic
number
• Electrons = same as atomic number
• Neutrons = subtract atomic number from atomic mass
PERIODIC TABLE PRACTICE
Element Symbol Atomic Number
Atomic Mass
Number of
Protons
Number of
Neutrons
Number of
Electrons
HydrogenBerylliumCarbon
Cobalt
Nickel
Krypton
THE PERIODIC TABLE
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Where are the following?• Atomic
number• Atomic Mass• Charges• Symbol• Name
See page 172
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In the periodic table elements are listed in order by their atomic number.
Metals are on the leftThe transition metals range from group 3 -12Non-metals are on the rightMetalloids form a “staircase” toward the right side.
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See page 171
Organization of the Periodic Table
Metals (left of zig zag line)Physical Properties of Metals: Shiny, good conductors of heat and electricity, ductile (make wires) and malleable (thin sheets). Easily lose electrons. Like to join with non-metals. Corrode (tarnish/rust).
Nonmetals (right of zig zag line)Physical Properties of Nonmetals: dull appearance, poor conductor, brittle (breaks easily), not ductile or malleable. Easily gain electrons. Like to join with metals, but will bond to other non-metals.
Metalloids (on both sides of zigzag line)Physical Properties of Metalloids: have properties of both metals and nonmetals. Solid, shiny or dull, ductile and malleable, conduct heat and electricity, but not very well.
THE PERIODIC TABLE
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Where are the following?• Metals• Non-metals• Transition
metals• Metalloids
See page 172
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Rows of elements (across) are called periods.All elements in a period have their electrons in the same general area around their nucleus.
Example: period 3 all have 3 electron shells
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See page 171
Organization of the Periodic Table
sodium magnesium aluminum
–Columns of elements are called groups, or families.• All elements in a family have similar properties and bond with other
elements in similar ways.• Group 1 = alkali metals• Group 2 = alkaline earth metals• Group 17 = the halogens• Group 18 = noble gases
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See page 171
Organization of the Periodic Table
17
18
Group 1 = alkali metalsvery reactive metalswant to give away 1 electronie: lithium, sodium, potassium...
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See page 171
Organization of the Periodic Table
1 2 17
18
Group 2 = alkali earth metalssomewhat reactive metalswant to give away 2 electronsie: beryllium, magnesium, calcium...
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See page 171
Organization of the Periodic Table
1 2 17
18
Group 17 = halogensvery reactive non-metalswant to accept 1 electronreact with alkali metalsie: fluorine, chlorine, bromine......
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See page 171
Organization of the Periodic Table
1 2 17
18
Group 18 = noble gasesSTABLE. Very non reactive gaseous non-metalsie: helium, neon, argon......
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See page 171
Organization of the Periodic Table
1 2 17
18
THE PERIODIC TABLE
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Where are the following?• Period• Group/Family• Alkali metals• Alkaline earth
metals• Halogens• Noble gases
See page 172
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Atoms gain and lose electrons to form bonds.The atoms become electrically charged particles called
ions.
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See page 173
Periodic Table & Ion Formation
Atoms gain and lose electrons to form bonds.Metals lose negative electrons & become positive ions.
Positive ions are called CATIONS.
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See page 173
Periodic Table & Ion Formation
Some metals are MULTIVALENT and can lose a varying number of electrons.
For example, iron, Fe, loses either two (Fe2+) or three (Fe3+) electrons
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See page 173
Periodic Table & Ion Formation
Atoms gain and lose electrons to form bonds.Non-metals gain electrons and become negative ions
Negative ions are called ANIONS
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See page 173
Periodic Table & Ion Formation
Atoms gain and lose electrons in an attempt to be STABLE.The noble gases are stable because they have FULL outer
shells of electrons. They don’t need to lose or gain any e-s.Atoms in each period want to have the same number of
electrons in their outer shell (VALENCE ELECTRONS) as the noble gases on the end of their period.
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See page 173
Periodic Table & Ion Formation
Bohr diagrams show how many electrons appear in each electron shell around an atom.
The first electron shell holds 2 electronsThe second electron shell holds 8 electronsThe third electron shell holds 8 electronsThe fourth electron shell holds 18 electrons
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See page 174
BOHR MODELS
The noble gas elements have full electron shells and are very stable = STABLE OCTET
Electrons appear in shells in a very predictable manner.
The period number = the number of shells in the atom.Except for the transition elements (family 3-12), the last
digit of the group number = the number of electrons in the valence shell.
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See page 175
Patterns of Electron Arrangement in Periods &
Groups
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•It has 2 + 8 + 8 = 18 electrons, and therefore, 18 protons.
•It has three electron shells, so it is in period 3.
•It has eight electrons in the outer (valence) shell.
BOHR MODELSWhat is the Bohr Model Diagram for Argon?
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