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Name _____________________ Date _________ Period ____. Valence Electron Interaction and Charges. The Role of Electrons in Bonding. The sharing or transfer of electrons is what holds atoms together in a compound Typically, only the electrons in the - PowerPoint PPT Presentation
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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