If I have a +2 oxidation number do I give up or accept electrons?​

I will give up the electrons

Explanation:

Consider the following rules:

1. An atom loses electrons if its oxidation number is positive.

2. An atom gains electrons if its oxidation number is negative.

3. An atom neither gains nor loses electrons if its atomic number is zero.

As I have an oxidation number that is oxidation number is positive, so, I will give up electrons.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.