Chapter 6: Ionic Compounds

What is an Ion? An ion is an atom with a charge The charge can be positive or negative. Ex: Li+1 or N-3

Why Form Ions? Atoms gain or lose electrons to become more stable. The amount of electrons gained or lost is related to the octet rule. (more on this much later)

Why make Ions??

Ionic Compounds An Ionic compound is formed between a positive and a negative ion Cation: any positive ion (typically metals) Anion: any negative ion (typically nonmetals)

How to Name Ionic compounds The Rules: Write the name of the metal first. If it is a transition metal (except Ag,Cd, Zn) you must use a roman numeral to indicate the charge of the transition metal If it is Sn or Pb you need a roman numeral even though they are not transition metals Write the name of the nonmetal second Change ending to “ide” If compound has a polyatomic ion, just copy down the name of the polyatomic ion without changing its spelling

Examples!

How to write Chemical Formula from the name: Rules: Use periodic table or polyatomic ion sheet to write down charges for each ion If charges are equal and opposite (+2/-2) then just combine them and write symbols next to each other. If charges are not equal and opposite (+2/-3) then use criss cross method

How to Criss Cross

Examples!!