Question

whats the mass of an atom that has 4 protons , 4 neutrons ,and 4 electrons

Answer 1

Atomic mass is equal to the number of protons and neutrons. Electrons have so little mass that they are practically negligible.
Atomic mass= 4+4= 8 AMU

Answer 2

The atomic mass would be 8..

Explanation :
which means the substance is is 8 beryllium , which is an unstable isotope of beryllium : the stable isotope is the one that contains 4 protons and 5 neutrons.

The number of electrons would be 4, and as this atom there is no overrall charge.

An overrall charge would only occur if one or more electrons were lost.

config is 1s2 2s2