Question

question
atomic number is defined as
answer
the number of protons in the nucleus
the number of electrons in the outermost shell
the number of neutrons in the nucleus
the number of protons plus the number of neutrons in the nucleus
i dont know yet

Explanation:

The atomic number of an element is defined as the number of protons in the nucleus of an atom of that element. This is a fundamental concept in chemistry.

Answer:

the number of protons in the nucleus