Question

How many times Hydrogen is lighter than air?

Answer 1

We know an atom consists of protons, neutrons, and electrons which have a certain mass. Air is made up of various gases. Every gas has some mass and volume. The less the mass of gas the lighter it is and vice versa. Density, mass, and volume are related to each other.

Complete answer:
As we know, Hydrogen is the first and the smallest element with an atomic number 1 and atomic mass of 1. All gaseous atoms have neutrons except Hydrogen.
On the other hand, the air is made up of various gases like Nitrogen, Oxygen, carbon-di-oxide, noble gases, etc. Air also has water vapour present in it. The masses of all these gases add up which increases the density of air. Dense gases are heavier and thus weigh more.
Hydrogen is lighter than each gas that is present in the air. So when the gases in the air are measured against hydrogen, the latter becomes lighter.
Therefore, Hydrogen is 14 times lighter than Air.

Additional information: lighter gases are called lifting gas. They are lighter than air that makes them rise to create buoyancy. These gases are used in balloons, airplanes, and airships. Helium is very commonly filled in balloons, but it is two times heavier than hydrogen.

Note:
The density of Hydrogen is $7\%$ the density of dry air which is 1.29 g/L. Hydrogen can be extensively used as lifting gas, but it is highly flammable. So many countries have restricted the use of hydrogen as a lift gas. Because of this helium is used although it is more expensive than hydrogen.