Only answer if you know for sure
where are the anion and cation written in an ionic compound?

a) the ion with the largest subscript in the formula is written first in the name of an ionic compound
b) the cation is written before the anion in the name and formula of an ionic compound
c) the anion is written before the cation in the name and formula of an ionic compound
d) the ion, cation, or anion with the greatest charge is written first in the name and the formula of an ionic compound

The cation is written before the anion in the name and formula of an ionic compound.

Option B

Explanation:

An ionic compounds are a chemical compound at which ions usually held together by an ionic bonds. Typically, a positively charged residue consists of metal cations, while a negatively charged residue consists of an anion or a poly-atomic ion. The ionic compound is mentioned first by a cation after with an anion. The cations have the same name as its element.

For example,  is called the potassium ion but simply 'K' refers potassium atom. Anion is called by the name of the element, removing the end part and adding "ide". For example,  is called fluorine, an element called fluorine. 'ine' was replaced with an 'ide'. To name the compound, the cation and anion names are added together. For example, NaF (sodium fluoride).

i think a, hope it .

explanation:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.