Respuestas
In a simple way and for everyone to understand, they will say that hot air weighs less or is lighter than cold air and, therefore, rises; A very clear example and that all have seen, is the smoke from the chimneys, which is lighter and less dense than the air in the surrounding atmosphere, rises.
In hot air balloons, what is done is to increase the temperature of the interior air of the candle with the burners, so that said air is lighter and less dense than the outside and pushes the balloon upwards.
In gas balloons, introduce helium or nitrogen in the candle, gases that are lighter than air in the atmosphere and produce the same lifting effect.
Debido a que al incrementar la temperatura sobre el aire del interior del globo, éste se hace menos denso que el que permanece en el exterior y por eso tiende a ascender.
geoplanet.