Ms. Shobhna conducted a science activity in following steps :
I : She made crystals of pure copper sulphate from
an impure sample.
II : She dissolved the crystals in pure water to make
a blue solution.
III : She added a metallic piece into the copper
sulphate solution and after some time colour of
the solution changed to green.
Which of the following statements is correct regarding
this activity?
AStep I involves a physical change while steps
II and III involve chemical changes.
BSteps I and II involve physical changes while
step III involves chemical change.
CAll the steps involve physical changes.
DAll the steps involve chemical changes.