Question

1. the atomic number, or ____ number, is described as the number of ____ in the nucleus of a chemical element.

a proton, protons
b photon, photons
c neutron, neutrons
d electron, electrons

Explanation:

The atomic number of an element is defined as the number of protons in the nucleus of an atom of that element. Protons are positively - charged particles located in the nucleus.

Answer:

A. protons, protons