# Given that "atomic numbers, Z", and numbers of neutrons are integral, why do we get non-integral atomic masses? What is the relationship between Z, and the number of electrons?

Jun 7, 2017

$i .$ $\text{Atomic number, Z} \ldots \ldots \ldots .$
$i i .$ $\text{Atomic mass} \ldots \ldots \ldots .$
And of course $Z$, specifically the number of massive, positively charged particles in the element's nucleus is ALSO equal to the number of electrons, negatively charged particles conceived to whiz about the nuclear core in the NEUTRAL atom. Why is $Z$ equal to the number of $\text{electrons}$?
The atomic mass is the weighted average of the individual isotopes that characterize the neutral element; for the heavier elements there is usually an isotopic mix. The position of the element in the Table flags the type of element we are dealing with: alkali metal or alkaline earth metal; $\text{Group 3}$ or $\text{f-element metal}$; transition metal; main group element; or inert gas.