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