Ionic formulas

What is the correct formula for the compound, lithium oxide?

• LiO

• Li₂O

• Li₂O₂

• LiO₂

What is the formula for manganese(III) oxide?

• MgO

• Mg₂O₃

• MnO

• Mn₂O₃

From the following ionic compounds, choose the name-formula pair that is not correctly matched.

• sodium sulfide  Na₂S

• 
  sodium sulfate 
  Na₂SO₃

• ammonium nitrate 
  NH₄NO₃

• calcium oxide  CaO

Name the following ionic compound: MgSO₄

• magnesium sulfoxide

• magnesium sulfate

• magnesium sulfide

• magnesium oxide

Name the following ionic compound: Cr(NO₂)₃

• chromium nitrite

• chromium III nitride

• chromium III nitrite

• chromium nitride

The formula of calcium phosphate is 

• Ca₃(PO₄)₂

• CaPO₄

• Ca₂(PO₄)₃

• Ca₃PO₄

The chemical formula of Iron (III)bromide is

• FeBr₃

• FeBr

• Fe(III)Br

• Fe₂Br₃

The chemical compound for sodium phosphate would be:

• Na₂PO₄

• NaPO₄

• Na₃PO₄

• Na(PO₄)₃

How do the following two elements bond together?
Na¹⁺  F^1-         

• Na₁F₂

• NaF

• NaF₃

• Na₃F

How do the following two elements bond together?
Cr³⁺  O^2-   

• CrO

• Cr₃O₂

• Cr₂O₃

• CrO₃