Define the two forces: gravity and the normal force

Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun.

The normal force is the force that surfaces exert to prevent solid objects from passing through each other. Normal force is a contact force. If two surfaces are not in contact, they can't exert a normal force on each other.

The gas would begin to expand, and eventually the can would burst or explode.

Hydrogen is the most abundant element on the periodic table..hope it .