If sodium has atomic number 11 and mass number of 23, then the number of protons, neutrons, and electrons in an uncharged atom is :
11,12,11
The number of protons and the number of electrons is equal to the atomic number of an uncharged atom. The difference between the mass number and atomic number gives us the number of neutrons.
Hence here, no of protons = no of electrons = atomic number = 11
Number of Neutrons = Mass number - Atomic Number = 23 -11 = 12