Which of the following is not required in a chemical reaction?

a.

atomic nuclei

c.

products

b.

reactants

d.

energy

atomic nuclei:

The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. The atomic nucleus was discovered in 1911 by Ernest Rutherford based on the 1909 Geiger-Marsden gold foil experiment.

The correct answer is C. Products, among the choices, are not require in a chemical reaction since it is what the process produces. For the reaction to occur, the reactants are important and the energy required for the reaction to happen which is the activation energy.