Samples of four metals A, B, C and D were taken and added to the solutions given in the following table, one by one. The results obtained are as follows:

Metal	Iron (II) sulphate	Copper (II) sulphate	Zinc sulphate	Silver nitrate
A	No reaction	Displacement
B	Displacement		No reaction
C	No reaction	No reaction	No reaction	Displace
D	No reaction	No reaction	No reaction	No reaction

Use the above table to answer the following questions about metals A, B, C and D:

(i) Which is the most reactive metal?

(ii) What would you observe when metal B is added to a solution of copper (II) sulphate?

(iii) Arrange the metals A, B, C and D in the order of decreasing reactivity.

Element ‘M’ forms a chloride with the formula MCl₂ which is sold with high melting point. To which group of the Periodic table does the element ‘M’ belong?

Define the terms: (i) mineral (ii) ore, and (iii) gangue. .

State reasons for the following observations:

(a) The shining surface of some metals becomes dull when exposed to air for a long time.

(b) Zinc fails to evolve hydrogen gas on reacting with dilute nitric acid.

(c) metal sulphides occur mainly in rocks but metal halides occur mostly in sea and lake waters.

Four metal A, B, C and D are added to the following aqueous solutions one by one. The observations made are tabulated below:

Answer the following questions based on the above observations:

(a) Which is the most active metal and why?

(b) What would be observed if B is added to a solution of copper (II) sulphate and why?

(c) Arrange the metal A, B, C and D in order of increasing reactivity.

(d) The container of which metal can be used to store both zinc sulphate solution and silver nitrate solution?

(e) Which of the above solutions can be easily stored in a container made up of any of these metals?