Assuming we're talking about the air around us, the gas you breathe in is actually a mixture of gases. Roughly 80% of it is nitrogen gas which and a little under 20% of it is oxygen which is the part we need. About 1% of the atmosphere is neither oxygen or nitrogen and crudely speaking is "everything else that's in the air", about 0.05% is carbon dioxide and there are small amounts of xenon, helium, methane etc.
This gas is oxygen from air.
yes oxygen is the gas that helps us breath without it we would die
Carbon dioxide
carbon dioxide
Nitrogen.
the gas is may be another chemical that the fish can breath at the surface an can help to make the fish can breath at small air and big water.
Oxygen
carbon dioxide
Your breath is a gas
Your breath is a mixture of gases (including a combination of nitrogen, oxygen, carbon dioxide, and a few inert gases). ITS A GAS IT IS NOT LIQUID YOU DUBM @$$ NOT THAT HARD
breath
You use your lungs to breath. Your heart pumps the blood round your body (including into and out of the lungs where gas exchange occurs when you breath).