One correct thging is that there are the same amount of positive and negative atoms
Calcium has the greatest mass of the first twenty elements with a mass of approximately 40.08
I think it’s Object 3
Hopefully this helps
Answer: The reaction is exothermic
The
value is negative.
Heat is a product.
Explanation:

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and
for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and
for the reaction comes out to be negative.
The substances which are written on the left side of the arrow are reactants and the substances which are written on the right side of the arrow are products. Thus heat is a product.