Answer:
4
Step-by-step explanation:
An atom with atomic number of 4 will have a proton number of 4.
Atomic number is the number of protons in an atom. Therefore, when given the atomic number, it shows the number of protons in the atom.
- The number of protons is the number of positively charged particles in the nucleus of an atom.
- The atomic number is used to arrange elements in their right position on the periodic table.