All sodium atoms have 11 protons in the nuclei of sodium Adams contains 12 neutrons and others contain 11 these different forms of sodium are called?

Isotopes

Atoms of the same element; number of protons remain the same, number of neutrons vary. Chemical properties remain the same. Atomic mass varies.

Na sodium with 11 neutrons = atomic mass of 22

With 22 neutrons the mass is 23.

Both have 11 protons in the nucleus.

4, two dominant and two recessive