6. When an atom gains or loses an electron is becomes charged and is called an ion.
7. Magnesium chloride is a compound which is composed of positive and negative ions.
8. SO2 is not an ionic compound because they are two nonmetals which makes it a covalent bond.
9. (Ca) has 2 valence electrons, (Al) has 3 valence electrons, (Rb) has 1 valence electron, (O) has 6 valence electrons, (S) has 6 valence electrons, and (I) has 7 valence electrons. Calcium oxide CaO, aluminum oxide AlO2, rubidium sulfide SRb2, and aluminum oxide Al2O3.
