Chemical Bonding

Lewis Dot Structures Diagrams that represent atoms and their valence electrons Contains: 1) Chemical Symbols represents the atom 2) Dots= valence electrons 3) Specific way in which dots are placed

Compounds - two or more different elements chemically combined (METAL AND SOMETHING ELSE)

• Binary compound – compound composed of two different elements ( metal + non-metal)

Chemical Formulas – Shorthand way of writing compound names – Combination of elemental symbols and numbers – Subscript “ written below” – tells how many ATOMS of that element are present in the compound – no subscript, only 1 atom of that element present • COUNTING ATOMS:

– NaCl – H2O2

H2O CO2 Ba(OH)2

MgSO4 3 Pb(NO3)2

• All atoms want to become chemically stable( AKA: Have a full last energy level) • Atoms WANT to lose, gain, or SHARE e’s to become chemically stable – OCTET- most atoms want an octet—to have 8 valence e’ in last energy level

–DUET- some atoms want two valence e’ to be chemically stable ( H, He, Li, Be, B)

• When an atom gains, loses, or share’s its electrons it forms an attraction between atoms: – Chemical bond – the attraction formed between two atoms that gain, lose, or share electrons

• Atoms with less than 4 valence electrons lose their valence electrons ( Gr 1,2, & 13) • Atoms with more than 4 valence electrons gain valence electrons ( Gr 15, 16,17)

• Atoms with four (GR 14) Likes to share valence electrons

• Ion- an atom that has lost or gained electrons- (AKA: an atom with an OVERALL CHARGE) – Negative ion: ANION- atom that has gained valence electrons ( non-metals) – Positive ion: CATION - atom that has LOST valence electrons anion [ metals]

• Ion symbols contain the elemental symbol a positive or negative charge- written as a superscript • EX: Na1+ O2- Mg2+ N3-

An oxidation number is a number assigned to an element to show it’s Elements in the SAME group have the same oxidation numbers

GR1

1+

GR2

2+

GR13

3+

GR14

4+ or 4-

GR15

3-

GR16

2-

GR17

1-

GR18

0