Hydrogen – Solutions

1) Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

Solution

Hydrogen is the first element of the periodic table having configuration 1s¹ similar to group 1. It shows a resemblance in properties with alkali metals. So, it can be placed with alkali metals in group 1 of the periodic table. On the other hand, the electronic configuration of hydrogen shows that is is short of one electron of the nearest noble gas configuration 1s² (He). It forms covalent bonds (H₂ , Cl_{2 ,} Br₂) as well as ionic binds(Na+ H^– , Na⁺ Cl^–) like halogens. It forms H⁺ ion by losing electrons and H^– ion by gaining electrons. On the basis of its electronic configuration , hydrogen can be placed with alkali metals in group 1 as well as with halogens in group 17 of the periodic table.

2) Write the names of the isotopes of hydrogen.

What is the mass ratio of these isotopes?

Solution

Hydrogen has three isotopes .