Which count of subatomic particles gives an atom its unique identity as an element, and represents its atomic number? a. the number of protons b. the number of neutrons c. the number of electrons d. the number of neutrons plus the number of protons

 a. the number of protons

Explanation:

Atomic number is defined as the number of protons or number of electrons that are present in an electrically neutral atom.

Atomic number = Number of electrons = Number of protons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

In an atom, when electrons are lost, the atom gains a positive charge and forms cation. In an atom, when electrons are gained, the atom occupies a negative charge and forms anion.

Hence, neutrons and protons affects the mass number and electrons affects the charge on an atom. The atomic number of an element is determined by the number of protons.