Hydrogen gas (H2) can be found in trace amounts in Earth's atmosphere.

Whh of these statements describes a physical property of hydrogen?

(A) Hydrogen is found in acids.

(B) Hydrogen gas is highly flammable.

(C) Hydrogen reacts with oxygen to form water.

D

Hydrogen gas is less dense than oxygen gas.

D. Hydrogen gas is less dense than oxygen gas.

Explanation:

Earth's atmosphere is mainly comprised of two gases namely nitrogen (78%) and oxygen (21%). The proportion of hydrogen is very little because its density is significantly low. So, it moves upward lost in the space. According to an estimate, approximately 95000 tonnes of hydrogen is lost every year.