* 11 protons: These are positively charged particles that determine the element's identity. Sodium's atomic number is 11, meaning it has 11 protons.

* 12 neutrons: These are neutral particles that contribute to the atom's mass. The number of neutrons can vary, leading to isotopes of the same element. Sodium-23, the most common isotope, has 12 neutrons.

Important Note: The electrons are not in the nucleus. They orbit the nucleus in shells.