How many protons and neutrons are there in Magnesium?
12 and 12 to 14.
As described in the book “Nature’â„¢s Building Blocks: an A-Z guide to the elements”, the chemical element Magnesium (Mg) has 12 protons ‘â€œ which is its atomic number. The number of neutrons, however, may vary from 12 to 14. The number of neutrons in an element defines its isotope. Magnesium has three natural isotopes: magnesium-24 (the most abundant, representing 79% of all Mg), magnesium-25 (10%) and magnesium-26 (11%).