General Knowledge - General Science - Discussion

As deep sea divers are under very high pressure of water, at that pressure oxygen are not able to dissolve in our blood so helium is used to fulfill the requirement.

Helium is an inert gas and is not toxic. However breathing pure helium is dangerous because it excludes needed oxygen. Deep sea divers can remain at depth only for controlled periods and must come up slowly and even remain at specified depths to avoid the bends. When ordinary air is used for diving the oxygen in the air is used up by the body but the nitrogen builds up to a new equilibrium state at the higher pressure required at great depths.

One danger that deep sea divers faced was that if they adjusted their air control valves improperly their suit might inflate preventing their hands from reaching the controls to correct the problem. They would then race all the way to the surface like a giant bubble. The excess nitrogen would then come out of tissues and form bubbles (like the fizz in a opened can of soda) in the blood causing the bends and great pain with possible death.

The diver could be placed in a re-compression chamber and pressurized to squeeze the nitrogen bubbles back into the tissues for controlled release during gradual decompression. The expanding nitrogen bubbles in tissues during rapid decompression may also drive away necessary oxygen leading to bone necrosis (bone death). One solution would be to use pure oxygen rather than pure air.

However pure oxygen can be toxic at great concentrations at depth. Therefore oxygen can be mixed with helium to reduce oxygen concentration while eliminating nitrogen. During controlled decompression the helium would also diffuse out of tissues and the lungs more easily than nitrogen avoiding the bends. Use of helium for relatively shallow scuba diving would likely permit longer diving times with less threat of the bends.

Since helium is a inert gas and lighter in weight. So it make oxygen up so that driver can respire properly and if it get mix with blood it have no bad effect and it is also not poisonous gas for human body while respiration.

Increased pressure in lungs during deep sea diving causes an increased solubility of all gases in the blood. On ascending too quickly, these gases can bubble out of the blood. This is a serious problem with nitrogen as the bubbles can rupture blood vessels causing "The bends".

The He atom is much smaller than the N2 molecule, has a smaller electron cloud and is less polarisable. It therefore is less soluble in blood than nitrogen and is preferred as the above dangers are reduced.

Thanks all of you for your explanations. They were really helpful.

What is the meaning of Inert gas and why they call?

Inert gas is what we breathe. The gas used by sea divers when they dive is called inert gas.

The ionic bond is strong bond not covalent bond.

Argon and Krypton being inert gases can't be used since they dissolve in blood with increasing pressure.

Helium is used by sea diver instead of Nitrogen because helium is not react with blood while nitrogen react with blood this cause pain in human body so helium is used because it cause less pain.