What effect does cutting down forests have on the carbon dioxide levels in the atmosphere?

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

What changes occur in the reaction indicated by the equation? check all that apply. the hydrogen nucleus loses protons. the oxygen nucleus gains protons. the bond in h2 is broken, and new bonds are formed between hydrogen and oxygen atoms. each electron associated with a hydrogen atom is shared with an oxygen atom.