SOME PLEASE HELP The law of conservation of energy states that energy cannot be created or destroyed. Which of the following is true in an exothermic reaction?
a. Heat plus the chemical energy of the reactants is converted into the chemical energy of the products.
b. The chemical energy of the reactants is converted into heat plus the chemical energy of the products.
c. The total amount of energy before the reaction is greater than the total amount of energy after the reaction.
d. The total amount of energy before the reaction is less than the total amount of energy after the reaction.

It is A

Explanation:

Thats because if heat reacts to chemicals then it would be a chemical energy spreading onto other objects in its surroundings  

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

the answers would be

the first one and the second one