K shell

The K shell is the first energy level closest to the nucleus and can hold a maximum of 2 electrons.

Protons

Protons are positively charged subatomic particles found in the nucleus of an atom. They determine the atomic number of an element, which is the number of protons in the nucleus. It also contributes to the mass of the atom.

Neutrons

Neutrons are subatomic particles with no electric charge and are found in the nucleus of an atom along with protons. They play a critical role in determining the stability and mass of the nucleus.

Electrons

Electrons are subatomic particles with a negative charge and are found outside the nucleus of an atom in regions called electron shells or orbitals. Electrons do not significantly contribute to the mass of an atom.