Magnesium is metal in group IIA of the periodic table with the atomic number 12, an atomic weight of 24.312, a density of 1.74 Mg/m 3, and a melting temperature of 650 C. The electronic configuration ...

The most common stable isotope of magnesium has 12 neutrons — particles with a neutral charge — in each nucleus, giving this version of the element an atomic mass of 24. As a result ...

Some elements have more than one stable (nonradioactive) isotope—variants of the same substance, but with different numbers of neutrons in their atomic nuclei that alter the mass. (The element's ...