Name _____________________ Date _________ Period ____

Valence Electron Interaction and Charges

The Role of Electrons in BondingThe sharing or transfer of electrons is what holds atoms together in a compound

Typically, only the electrons in the outer energy level are used for bonding.

These electrons are called Valence Electrons

The outer energy level is called the Valence Shell

Comprehension CheckHow many electron shells does phosphorus

have? 3

How many valence electrons does phosphorus have?5

PWYR – Valence Schmalencetin

4arsenic

5strontium

2bromine

7

sodium1

tellurium6

gallium3

krypton8

BondingIonic Bonds – Results from the

complete transfer of electrons

Results in a formation of two charged atoms called ionsThe atom that gains electrons becomes negatively charged and is called an anion

The atom that loses electrons becomes positively charged and is called a cation

Octet RuleOctet Rule: atoms want to have a full valence

shell (8 valence electrons) Atoms react with one another in an attempt to gain

or lose electrons to fill their valence shell During a reaction, electrons can be shared or

completely transferred

Two optionsGain electrons to fill valence shell Lose electrons to reveal full shell below outer

shell (outer shell)

Oxidation NumbersOxidation Numbers tell us how many

electrons an atom is willing to lose or gainPositive oxidation numbers indicate that

the atom can lose that many electronsNegative oxidation numbers indicate

that the atom can gain that many electrons

Some atoms have more than one possibilityTransition Metals

Alkali and a Halogen Valence Electrons

Extra ElectronMissing Electron

valence electron = 1Easier to give away

for full valence shellCation = positive -getting ride of negative particleCharge = +1

valence electron = 7Easier to take in for full

valence shellAnion = Negative - taking in negative particle Charge = -1

Periodic TableGroups have same valence electrons

Same oxidation number

1+1

2

+2

+3

3 4

+/-4

5

-36-2

-1

70

8

Comprehension Check- To Gain or Not to GainNitrogen Beryllium Xenon carbon

Oxygen Lithium Chlorine Boron

Gain 3Lose 2None

Gain/Lose 4

Gain 2

Lose 1

Gain 1

Lose 3