physical science 1000 bonding. counting electrons total electrons and valence electrons valence...

Physical Science 1000

Bonding

Counting Electrons

Total Electrons and Valence Electrons

Valence Electrons – number of electrons in the outer shell of an atom

The valence Electrons are the only ones used in Bonding

Hey, ….. That number matches the group number on my periodic table in a way!!!!

Valence Electrons

1 valence e-

2 valence e-

3 va

lenc

e e-

4 va

lenc

e e-

5 va

lenc

e e-

6 va

lenc

e e-

7 va

lenc

e e-

8 va

lenc

e e-

Noble Gases

• Elements in group 8 on the periodic table

• Each has 8 electrons in its outer shell

• Each is very stable – they don’t react

....Se Mg. .. .Na . ...

Cl: .. ..

..Na . ...

Cl: ..+ Na+ -...Cl: ..

..

Ionic Bond

bond formed by the giving or

taking of electrons

Al3+

+ O2- Al2O3

Mg2+

Cl MgCl2+

Na+

N3+

NaN3+

Properties of Ionic Compounds

Formed from a metal and a non metal

Most are soluble in water

Form crystalline lattices

Covalent Bond

bond formed by the Sharing

of electrons

Properties of Covalent Compounds

Formed by two nonmetals

Solubility varies

The strongest bond

Br..: ...Br.. :...

+ Br..: ...Br.. :...

bonding pair

nonbonding pairs

Polar Covalent Bond

Bond formed with the unequal sharing of electrons due to one atom being more electronegative

Electrongeativity -The attraction an atom has for a pair of shared electrons

S+

S-S-

More Electronegative

Ionic bond

Covalent bondPolar Covalent bond