In an endothermic reaction products are <u>HIGHER </u>than reactants in potential energy and <u>LESS </u>stable.
Explanation:
Energy is input into the reaction in an endothermic reaction. This means the products are of a higher energy level than the reactants. Therefore the reaction increases Gibb's free energy and reduces entropy. Remember in thermodynamic stability involves an increase in entropy and a decrease in Gibbs free energy. Therefore the products are less stable than the reactants. This is why endothermic reactions do not occur spontaneously like exothermic reactions.
To know the density you also need to know the volume of the rock.
The answer is A :) homogeneous!
I think its 2-, it gained 2 electrons.