Answer:
It ignited in air to form water
Step-by-step explanation:
In the experiments of Cavendish, he discovered a gas lighter than air when he added certain metals to dilute acids. The gas when breathed is significantly different from air.
The gas is known to burn in air when it approaches a flame to form water hence the name 'inflammable air' was given to the gas. It was later called hydrogen which means 'water former'.