Please help me with these Chemistry questions.

Question

When calcium and chlorine react to form calcium chloride, which substance is reduced?

a, there is not enough information

b. calcium chloride

c. calcium

d, chlorine

What happens to the oxidation number of an atom that is oxidized?

a. it does not change

b. it increases

c. it decreases

d, it may increase or decrease depending on the atom

In the reaction below, which is the oxidizing agent?

Answer 1

Ca + Cl₂ ==> CaCl₂

(d) Cl₂ is reduced because it goes from an oxidation number of zero, to an oxidation number of 1-.

When an atom is oxidized the oxidation number of that atom (b) increases

2Na(s) + S(s) ==> Na2S(s)

Na goes from an oxidation number of zero to an oxidation number of 1+. It was oxidized. (reducing agent)

S goes from an oxidation number of zero to an oxidation number of 2-. It was reduced. (oxidizing agent)

The OXIDIZING AGENT is S.