Which of the following factors determines the size of an atom?

Which of the following factors determines the size of an atom?
(a) The volume of the nucleus;
(b) the volume of space occupied by the electrons of the atom;
© the volume of a single electron, multiplied by the number of electrons in the atom;
(d) The total nuclear charge;
(e) The total mass of the electrons surrounding the nucleus.

Answer:

(b) the volume of space occupied by the electrons of the atom.