In the electrolytic refining of copper metal,which of the following decreases in weight?

In the electrolytic refining of metals, the insoluble impurities present in the impure metal settle down at the bottom of the container below the anode. What is this called?

$A$ metal $E$ is stored under kerosene oil. When a small piece of it is left open in the air,it catches fire. When the product formed is dissolved in water,it turns red litmus blue.
$(i)$ Name the metal $E$.
$(ii)$ Write the chemical equations for the reaction when it is exposed to air and when the product is dissolved in water.
$(iii)$ Explain the process by which the metal is obtained from its molten chloride.

Which of the following metals are obtained by electrolysis of their molten chlorides?
$(i) Na, (ii) Ca, (iii) Fe, (iv) Cu$

Which of the following methods is used for the concentration of ore?

Generally,in what forms are the elements present in the lithosphere?