Question

helium is used in divers in sea reason is explain by which scientist

Answer 1

Divers carry cylinders on their backs when going into the sea. Those cylinders often referred as oxygen cylinders are actually of mixture of gases and not pure oxygen. The normal compressed gas contains 78% nitrogen and 21% oxygen. As diver goes down, the pressure of gas increases.  If the diver uses these gases, he would experience narcosis,a condition of slowed critical thinking ability, due to effect of nitrogen on human body at high pressure.

Hence, nitrogen is replaced with helium as helium is inert, has low viscosity and low narcosis effect.