What does the atomic number tell us about an atom?

Question

The atomic number tells us how many protons and neutrons are in a neutral atom or element
The atomic number tells us how many protons and electrons are in a neutral atom or element
The atomic number tells us the mass of the atom or element

Answer 1

The atomic number tells us how many protons and electrons are in a neutral atom or element.

In a neutral atom, the number of electrons equals the number of protons, which is the atomic number. Therefore, the atomic number is a key identifier of an element and dictates its position in the periodic table. The atomic number does not directly indicate the number of neutrons, as that can vary among isotopes of the same element.