Hot Air Balloons Explained! |Charles' Law
Hot air balloons are based on a very basic scientific principle: Warmer air rises in cooler air. Essentially, hot air is lighter than cool air, because it has less mass per unit of volume.
Jacques Charles was a French physicist, who generally formulated this law in the year 1780.
According to him,
"when the pressure of a gas is held constant, increasing its temperature increases its volume."