(a)
Chloroethene has a melting point of -154 °C
All types of PVC melt at temperatures over 100 °C
Explain why PVC melts at a higher temperature than chloroethene.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

When a scientific theory has been tested and proved by the scientific community, it becomes a law

How can carbon move from "land" to bodies of water? describe the way human impact has lead to increased levels of co2 in the atmosphere.