UNIT 2 FORMULAS TO KNOW

Valence electrons

outer s+p

What ions do metals form?

cations

What ions do nonmetals form?

anions

Fixed Charge on Transition Metals

(+2) Al, Zn, Ag, Cd

Per_ate

same charge, 1 more oxygen

-ate

oxygens, charges

-ite

same charge, 1 less oxygen

hypo_ite

same charge, 2 less oxygen

Adding a hydrogen

+1 charge per H

Metals and polyatomic ions

keep their names

Non-metals

change ending to “-ide”

Transition metals

roman numerals for charge

later exceptions

Covalent compounds

nonmetals (metalloids)

ionic compounds

metal + nonmetal (polyatomic)

1 atom

mono-

2 atoms

di-

3 atoms

tri-

4 atoms

tetra-

5 atoms

penta-

6 atoms

hexa-

7 atoms

hepta-

8 atoms

octa-

9 atoms

nona-

10 atoms

deca-

Main Group, Ag, Zn, Polyatomic (YES)

metal + nonmetal (ide) or polyatomic ions

Transition Metal (NO)

Metal (charge) + Nonmetal (ide) or polyatomic ions

Nonmetal + Nonmetal

Prefix-nonmetal + Prefix-nonmetal (ide)

Formula mass

sum of all element mass x number of each

Percent composition

percent composition of one element = mass of one element / mass of compound x 100%

empirical formula

lowest whole number ratio

molecular formula

counting all atoms

mass of a hydrogen atom

1 proton: 1 amu

Avogadro’s number (also called a?)

6.02 × 10²3, mole

Avogadro’s number changes mass in

amu/atom to g/mole