Four groups of students were assigned separately the experiment of interaction of iron nails with a solution of copper sulphate. Each group recorded the observations as given b elow in the table.
Group of
students |
Initial
colour of
solution |
Final
colour of
solution |
Changes in
the iron
nail |
A |
Blue |
Colourless |
Grey coat |
B |
Green |
Green |
Brown coat |
C |
Blue |
Blue |
Brown coat |
D |
Blue |
Light
green |
Brown coat |
Which group of students recorded all the observations correctly?
(A) A (B) B (C) C (D) D