Sodium has 12 neutrons in its most common isotope, which is sodium-23. To determine the number of neutrons in an element, you can use the formula:
Number of Neutrons = Atomic Mass – Atomic Number
Sodium has an atomic number of 11, which means it has 11 protons. The atomic mass of the most abundant isotope of sodium is approximately 23. By subtracting the atomic number from the atomic mass, you get:
23 (atomic mass) – 11 (atomic number) = 12 (neutrons)
Hence, sodium contains 12 neutrons in its nucleus.