Question

Explain in detail the controversy behind the placement of Hydrogen in the modern periodic table.

Answer 1

• Hydrogen (H) is the first element in the periodic table, and it belongs to group 1.
• The electronic configuration of Hydrogen is $1s^1$. It has one electron and one proton.
• It is the only element not having a neutron.
• It possesses the properties of both alkali metals and halogens.
• Like alkali metals, it is ready to lose an electron and like halogens, it is ready to gain an electron.
• So it became controversial for the placement of Hydrogen in the modern periodic table.