The atomic number of an element represents the number of protons in its nucleus. In the case of sodium, which has an atomic number of 11, it means that sodium has 11 protons.
The atomic weight of an element represents the average mass of all the isotopes of that element, taking into account their abundances. For sodium, with an atomic weight of 23, it means that the average mass of sodium atoms is 23 atomic mass units (AMU).
Since the number of protons in an atom is equal to its atomic number, we know that sodium has 11 protons (p+).
To determine the number of neutrons (n0), we subtract the number of protons from the atomic weight. In this case: Number of neutrons (n0) = Atomic weight - Atomic number = 23 - 11 = 12
Therefore, sodium has 11 protons (p+), 12 neutrons (n0), and the number of electrons (e-) is also 11 because in a neutral atom, the number of electrons is equal to the number of protons.