Atomic Number Calculator
Find atomic numbers, calculate number of protons, neutrons, and electrons for any element.
Element Lookup
Subatomic Particle Calculator
Common Elements:
Subatomic Particles
6
Protons
6
Neutrons
6
Electrons
Protons (Z)
6
Neutrons (N)
6
Electrons
6
Nucleons (A)
12
Formulas:
Protons = Atomic Number (Z)
Neutrons = Mass Number (A) - Atomic Number (Z)
Electrons = Protons (for neutral atom)
Element Reference
| Symbol | Name | Atomic # | Atomic Mass | Category |
|---|---|---|---|---|
| H | Hydrogen | 1 | 1.008 u | Nonmetal |
| He | Helium | 2 | 4.003 u | Noble Gas |
| Li | Lithium | 3 | 6.941 u | Alkali Metal |
| Be | Beryllium | 4 | 9.012 u | Alkaline Earth |
| B | Boron | 5 | 10.81 u | Metalloid |
| C | Carbon | 6 | 12.01 u | Nonmetal |
| N | Nitrogen | 7 | 14.01 u | Nonmetal |
| O | Oxygen | 8 | 16 u | Nonmetal |
| F | Fluorine | 9 | 19 u | Halogen |
| Ne | Neon | 10 | 20.18 u | Noble Gas |
Understanding Atomic Number
The atomic number (Z) is the number of protons in the nucleus of an atom. It uniquely identifies a chemical element. For a neutral atom, the number of electrons equals the number of protons. The mass number (A) is the total number of protons and neutrons (nucleons) in the nucleus. Different isotopes of an element have the same atomic number but different mass numbers due to varying numbers of neutrons.