Write the name of the following ionic compounds

1 - Sodium Hydroxide. This is because Sodium is alone and the first element never uses mono. OH always forms Hydroxide.

2 - Dicobalt Phosphide or Cobalt (II) Phosphide. This is because doing swap and drop gives cobalt the subscript of two and phosphorus, which originally has three valence electrons, cancels out the valence electrons given by cobalt.

3 - Lead (IV) Carbonate. Once again, doing swap and drop reveals that lead has a charge of four. The second term is carbonate because if you reference your formula sheet, CO3 is carbonate.

4 - Magnesium Fluoride. This is because, once again you perform Swap and Drop. Magnesium has a charge of two, so the two cancel out while fluorine has a charge of one.

5 - Dilithium Sulfite. You do not perform swap and drop as it is not a metal and non metal, thus applying the correct prefixes. It is sulfite rather than sulfate as SO4 is sulfate.

6 - Ammonium Phosphate. Once again, reference your formula sheet/reference sheet. Swap and drop shows that phosphate has a charge of three, cancelling out the swap and drop between the polyatomic ions.

7 - Iron (II) Oxide. Once more, preform swap and drop by swapping the two valence electrons in Oxygen to roman numerals for Iron.

8 - Calcium Sulfate. Swap and drop would not effect anything as both share a charge of two valence electrons, thus leaving you to reference the reference sheet for names.

9 - Silver Nitride. Once more, preform swap and drop but the three would cancel out with Nitrogen’s three valence electrons.

10 - Sodium Sulfide. If you preform swap and drop, you will find that sulfur also has two valence electrons, thus cancelling those from sodium.

Hope this helps!

Yes you are correct use the scientific method