Question

mention the period of the modern periodic table to which the mg and al belongs to? and why?

Answer 1

Magnesium belongs to the third period of the periodic table. We know that the period in which an element is present is the same as the number of the valence shell. The atomic number of magnesium is 12 and its electronic configuration is 2, 8, 2. So, the third shell in magnesium is the valence shell, and hence it belongs to the third period of the periodic table.