* Protons: 11 protons located in the nucleus. Protons are positively charged particles.

* Neutrons: 12 neutrons located in the nucleus. Neutrons have no charge.

* Electrons: 11 electrons orbiting the nucleus in specific energy levels or shells. Electrons are negatively charged particles.

Here's a breakdown:

* Atomic Number: The number of protons defines the element. Sodium has an atomic number of 11, meaning it always has 11 protons.

* Mass Number: The sum of protons and neutrons gives the mass number. Sodium usually has 12 neutrons, making its mass number 23 (11 protons + 12 neutrons = 23).

* Electrons: The number of electrons is equal to the number of protons in a neutral atom.

Important Note: There are different isotopes of sodium. Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons. For example, sodium-22 has only 11 neutrons, while sodium-24 has 13 neutrons.