Post on 02-Jan-2016
Chemical ReactionsIons, Molecules and Compounds
Forming Compounds
Noble gases are unlikely to take part in chemical reactions – WHY?
When atoms collide, electrons interact An atom may give up electrons = cation An atom may gain electrons = anion An atom may share electrons = one pair, two
pair or more
Forming Compounds Ionic Compounds
Composed of cations and anions Attraction is called an ionic bond Metal joined with non-metal Na+ joined with Cl-
Forming Compounds Molecular Compounds
Composed of pairs of electrons being shared Attraction is called a covalent bond Two non-metals O2- joined with O2-
Chemical Names and Formulas
Key Points to Remember: Metal + Non-metal = Ionic Bond Non-metal + Non-metal = Covalent Bond
Ionic Bond = Ionic Compound Covalent Bond = Molecular Compound
Chemical Names and Formulas Names and Formulas for Binary
Molecular Compounds Ends in “~ide”
Prefix System Mono is used only for the
second element Element that is more to the left
is written first If prefix ends in “o” or “a” and
is followed by an “o” , then the vowel on the prefix is dropped
Number Prefix
1 mono
2 di
3 tri
4 tetra
5 penta
6 hexa
Chemical Names and Formulas (p.161)
Ionic Binary Compounds – only have two elements present Ends in “~ide”
Polyatomic Ions – have more then two elements present
Name Chemical Formula
ammonium ion NH4+
hydroxide ion OH-
carbonate CO32-
nitrate NO3-
sulfate SO42-
hydrogen carbonate HCO3-
hydrogen sulfate HSO4-
phosphate PO43-
Multivalent Ions An
element that can form an ion in more than one way.
Element (ous) (ic)
Iron (Fe) +2 +3
Lead (Pb) +2 +4
Tin (Sn) +2 +4
Mercury +1 +2
Copper +1 +2