Question

2. An element's atomic number is the A. number of protons in an atom's nucleus. B. mass of the atom. C. weight of the atom. D. sum of the protons and neutrons in an atom.

Answer 1

An elements atomic number is the: Number of protons in the atom's nucleus.

Answer 2

A. number of protons in an atom's nucleus.

Step-by-step explanation:

The number of protons in the nucleus in an atom is the atomic number of the element and it is characteristic of a chemical element and determines its place in the periodic table.