Boiling means change from a liquid into a gas by adding heat energy.
Boiling is the very rapid conversion of a liquid into vapor by the violent evolution of bubbles.
The violent evolution of bubbles means a change from a liquid into a gas by adding heat energy.
What means a change from a liquid into a gas by adding heat energy?
(A) Evaporation of water
(B) heat is produced
(C) violent evolution of bubbles
(D) igniting fuel and oxidiser
(E) Water expanding
(F) a hemisphere is tilted away from the sun
(G) evaporative cooling
(H) degrees Celsius