Question

The mixture of gases used by deep-sea divers is:

• A. helium - oxygen
• B. oxygen - nitrogen
• C. hydrogen - nitrogen
• D. none of these

Answer 1

The correct option is A helium - oxygen

The mixture of helium-oxygen is used by deep-sea divers.

The main reason for adding helium with oxygen to the breathing mix is to reduce the proportions of nitrogen and oxygen to allow the gas mix to be breathed safely on deep dives.

Hence, option $A$ is correct.