Question

I am the lightest gas in all gases. my rank is first in the periodic table. if you react me with a gas who is life saver on earth, river will get overflow, guess who am I?

Answer 1

Answer:

Hydrogen

Explanation:

Hydrogen + oxygen = water

hydrogen is the first element

Answer 2

Answer:

Hydrogen

Explanation:

hydrogen is the first element of the periodic table.The formula of water is H2O.

I hope this is helpful