I wish to understand how to name binary (inorganic) compounds when given their formula. When I am a given compound like $\ce{B2F2}$ or $\ce{N2O4}$, I have little to no clue on how to write their chemical names. Similarly, I also trip up when trying to convert a given chemical name - say diboron difluoride - to its chemical formula.

Moreover, I have seen that a few times we do not need the numeric prefixes - as in lithium oxide or magnesium chloride - but sometimes we do - as in dinitrogentetroxide or iodine monochloride. So, I also need help understanding when to include numerical prefixes and when to not.

Please limit the answer to simple, binary, ionic and covalent compounds, and exclude hydrocarbons.

How can I deduce the name of a binary (inorganic) compound like $\ce{B2F2}$ or $\ce{N2O4}$, from the formula?

And how can I convert a chemical name like diboron difluoride to the chemical formula?

I don't see why we do not need the numeric prefixes in the cases of lithium oxide and magnesium chloride but we do with dinitrogen tetroxide and iodine monochloride.

Please limit the answer to simple, binary, ionic and covalent compounds, and exclude hydrocarbons.