What must occur in order for a chemical reaction to be specifically classified as endothermic instead of exothermic? A)Atoms are rearranged.

B)Chemical bonds are formed.

C)Energy is released in the form of heat.

D)Energy is absorbed in the form of heat.

An exothermic reaction creates heat.

The answer would be c) energy is released in the form of heat.

A chemical  reaction is classified as exothermic or endothermic based on the direction of heat flow during the reaction

The correct option for what must occur for a reaction to be classified as an exothermic reaction is option C

C) Energy is released in the form of heat

The reasons the above value is correct are;

An exothermic reaction is one in which energy in the form of light, heat or other forms because the sum of the energy in the product is less than the sum of energy contained in the reactants

Therefore, for a chemical reaction to be specifically classified as an endothermic reaction, instead of an exothermic reaction, is energy, in the form of heat (or light) must be released

The correct option is option C

Learn more about exothermic reaction here:

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a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o