If in the following diagram the substance is in solid form during state 1, what is happening during stage 4? the substance is melting or freezing. the substance is in the liquid state. the substance is in the gaseous state. the substance is boiling or condensing.

Answer is: The substance is boiling or condensing.

Stage 1 is solid state of substance.

Stage 2 is melting (from solid to liquid) or freezing (from liquid to solid state) of the substance.

Stage 3 is liquid state of substance.

Stage 4 is boiling (from liquid to gas) or condensing (from gas to liquid state).

Stage 5 is gaseous state of substance.

the answer is a! (2.9 x 10^-18 j) hope i could someone. : )