State changes take place among solids, liquids and gases. gas $\xrightleftharpoons[P]{R}$ liquid $\xrightleftharpoons[Q]{S}$ solid What changes are happening at P, Q, R and S?
- AP boiling, Q melting, R freezing, S condensing
- BP condensing, Q freezing, R boiling, S melting
- CP freezing, Q condensing, R boiling, S melting
- DP melting, Q boiling, R condensing, S freezing