Question

multiple select question
select all that apply
which statements describe how to write formulas for binary ionic compounds?

the symbol for the anion always goes first
the sum of the oxidation number of each ion multiplied by the number of ions in a formula unit must equal zero.
if no subscript is written, it is assumed to be one.
subscripts represent the number of ions of each element in a formula unit of the compound.
subscripts represent the magnitude of the charge on each ion

Explanation:

• Binary ionic formulas list cations first, so the first statement is wrong.
• For neutral compounds, the sum of (oxidation number × ion count) must equal 0, so this is correct.
• Unwritten subscripts are assumed to be 1, this is a standard rule.
• Subscripts indicate the number of each ion in the formula unit, this is correct.
• Subscripts are not the same as ion charge magnitude (they balance charges, not match them directly), so the last statement is wrong.

Answer:

• The sum of the oxidation number of each ion multiplied by the number of ions in a formula unit must equal zero.
• If no subscript is written, it is assumed to be one.
• Subscripts represent the number of ions of each element in a formula unit of the compound.