Food cans are coated with tin and not with zinc because

You are given a hammer,a battery,a bulb,wires,and a switch.
$(a)$ How could you use them to distinguish between samples of metals and non-metals?
$(b)$ Assess the usefulness of these tests in distinguishing between metals and non-metals.

What chemical process is used for obtaining a metal from its oxide?

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

What would you observe when zinc is added to a solution of iron $(II)$ sulphate? Write the chemical reaction that takes place.

Samples of four metals $A$,$B$,$C$ and $D$ were taken and added to the following solutions one by one. The results obtained have been tabulated as follows.

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

Use the table above to answer the following questions about metals $A$,$B$,$C$ and $D$:
$(i)$ Which is the most reactive metal?
$(ii)$ What would you observe if $B$ is added to a solution of Copper $(II)$ sulphate?
$(iii)$ Arrange the metals $A$,$B$,$C$ and $D$ in the order of decreasing reactivity.