How can I assign oxidation numbers to each of the atoms?
Without knowing which atoms in particular, here are a few rules:
- Solid metals and diatomic gases always have an oxidation number (ON) of zero.
- Alkali metals (column #1) always have an oxidation number of +1
Halogens, following a metal, have an ON of -1
Hydrogen, acting like a metal, will have a charge of +1 and oxygen will have a charge of -2
Peroxides made with a column 1 metal and oxygen for ex:
#K_2O_2#, or #H_2O_2#, the oxygen will have a -1 charge. There are peroxides with column 2 metals, for example #MgO_2#, the Oxygen will still have a charge of -1.
Metal hydrides, made with a metal first and a hydrogen last, for example,
#NaH#, the H will have a charge of -1
- Count the polyatomic atoms on the back of the high school periodic table, as what they are to help determine any other atom in a formula.