That depends on the number of protons. It also depends whether the atom has gained or lost electrons to form an ion.
Carbon is element number 6; it has 6 protons and 6 electrons.
Lead is element number 82; it has 82 protons and 82 electrons.
The neutral atom of promethium contain 61 electrons.
The very inner shell of an atom is the 1st shell and can only contain 2 electrons.
The neutral atom of ununseptium contain 117 electrons.
the nucleus does not contain electrons of the atom.
10
12
a neon atom has 10 electrons , 10 protons , and 10 neutrons. its mass no. is 20 and atomic no. is 10. it is a stable atom.
Neutral atom of magnesium has 12 electrons.
two
3
2
18