Respuesta :

Atomic number means the number of protons (p). So the answer is B) because the thats the only one with p = 4

Answer: B.

Explanation:

Atomic number of an atom is given by number of protons in the nucleus of the atom.

In a neutral atom, number of electrons = number of protons

option A- atom has 7 protons, thus atomic number is 7

option B- atom has 4 protons, thus atomic number is 4

option C- atom has 3 protons, thus atomic number is 3

Thus, B has atomic number 4. The element Beryllium has atomic number 4