Energy(heat)

[Miike012]

I have a question about energy.

If temperature is raising does this mean that heat is being absorbed or evolved?

and if heat is being absorbed this means that temp is raising?
and temp is lowering if heat is being evolved???

[danago]

If something is increasing in temperature then it is generally absorbing heat. However, things can increase in temperature without heat transfer too. Consider the first law of thermodynamics:

\Delta U=Q+W

where U is the internal energy. If a process is adiabatic (i.e. no heat transfer allowed, Q=0), then the internal energy can still be increased if work is done on the system (W>0), for example by compressing a gas in an insulated container.

If heat is being absorbed then it does not necessarily imply that the temperature is increasing. Consider any pure liquid at its boiling point and at constant pressure -- as more heat energy is transferred to the system, the temperature will remain constant until all the liquid has evaporated.