Explain why, the first period of the modern periodic table has only two elements whereas second period has eight elements

Question

Philoid · Accepted Answer

The first period of the modern periodic table has only two elements because there are two elements in the first period Hydrogen and Helium. In these two elements there is only one shell present and it can only take two elements. Second period has 8 elements because it has 2 shells and 2^nd shell will not take electrons more than 8.