Question

What is the atomic number of 1 proton, 1 neutron and 1 electron?

Answer 1

The atomic number of an element is defined by the number of protons in its nucleus. In the case you provided, there is 1 proton. Therefore, the atomic number is 1. This corresponds to hydrogen (H), which is the simplest and most abundant element in the universe. The presence of a neutron and an electron does not affect the atomic number; it only pertains to the mass of the atom and its ionization state, respectively.