I just wanna know what does that even mean
Answer:
c. c. c c c c c cçcc. ccccccccc
Explanation:
ccc cc
<span>Ionic compounds form crystal lattices, not molecules. The term formula unit is used to indicate the simplest whole-number ratio of ions in the compound.</span>
Answer:
Oxidizing element: Mg
Explanation:
Reaction of magnesium and oxygen can be written as:

while writting chemical reaction between two atom or element then write their natural form i.e. how that atom or element exist in the nature.
eg. reaction of any element with Oxygen atom then we can not write directly O because oxygen exist in the nature in form of 
finding oxidation number each side:
Reactant side:
Mg=0;
O=0;
product side:
Mg=+2;
O=-2;
from above:
oxidation number of Mg is increasing hence this is oxidizing element