# The atomic number tells the number of what two items in an atom?

May 18, 2017

Well, $Z$, $\text{the atomic number}$ gives (i), the number of protons, massive, fundamental positively charged nuclear particles.

#### Explanation:

And (ii), the number of electrons, fundamental negatively charged particles of negligible mass that are conceived to whizz about the nuclear core; of course electrical neutrality demands that $Z$ and the number of electrons be equal.

$Z$ determines the identity of the atom.........Z=1,H; Z=2, He,,
$Z = 3 , L i \ldots \ldots \ldots \ldots \ldots \ldots \ldots \ldots \ldots . . Z = 92 , U$.

See

https://socratic.org/questions/why-do-all-isotopes-of-hydrogen-have-an-atomic-number-of-1#216989

for a description of $\text{isotopes}$, which are provide further details with respect to atomic structure.