Why do milk or tea raise when heated?

in case of tea its milk responsible for..

in milk there is a lot of fat, *(differ from cream)

when boiled.it comes to the upper part and makes a layer, which cut off the milk interface from atmosphere,

now the vapour and dissolved air, gets deposit under this fat layer and gives it a up-throw due to pressure,

this up-throw causes the rise in liquid near the upper layer,

(cream = fat + coagulated protein)

milk

Probably because milk has protein which entrap gases more efficiently, like water which has dissolved gases. When heated the gas is released.

probably because almost all objects expand when heated, iirc its because heat is actually vibration of the mmolecules and as they get hotter and thus more vibration, they need more space to vibrate in. thus they push against the other molecules and cause the total size of the object or substance to expand.

coz da electrons gain energy nd vibrate at greater speed

Bcz its feeling HOT!

try sitting on burning fire ... you'll kno y they raise ..lol