It is a true fact that ionic crystals are excellent insulators and can hold a large amount of heat before melting or boiling. The correct option among the two options that are given in the question is the first option. Salt is a great example of ionic crystals and we know that it takes a huge amount of time to melt or boil.
Answer:

Explanation:
The first step is:

Second step is:

Multiplying second step by 2, and adding both the steps, we get that:

Cancelling common species, we get that:

I suppose it false, since the oxidation involves the loss or removal of the electrons such forth it does not gain electrons.