3. Below is a report that was written for an experiment the teacher showed the class.

Mrs. Smith dropped a piece of very thin metal into a gas jar of chlorine gas. The metal shrivelled up then it went on fire. When the burning stopped a green solid could be seen in the bottom of the gas jar which wasn't there before.

(a) State two indicators of a chemical from the information above.

(b) The reaction had to be carried out in the fume cupboard. What does this suggest about the chlorine gas? 1​