Which metal burns with a dazzling white light when heated at a high temperature?

In the electrolytic refining of copper metal,what is used as the cathode?

$A$ metal $A$,which is used in the thermite process,when heated with oxygen gives an oxide $B$,which is amphoteric in nature. Identify $A$ and $B$. Write down the reactions of oxide $B$ with $HCl$ and $NaOH$.

Name the metal which:
$(a)$ becomes blackish after a certain time.
$(b)$ develops a green coating on exposure to air.
$(c)$ does not corrode at all.
$(d)$ is used in making steel.
$(e)$ is non-lustrous.

Write chemical equations for the reactions taking place when:
$(i)$ Iron reacts with steam.
$(ii)$ Magnesium $(Mg)$ reacts with dilute $HCl$.
$(iii)$ Copper is heated in air.

What type of reaction occurs when sulfur dioxide $(SO_2)$ reacts with an acidic solution of potassium dichromate $(K_2Cr_2O_7)$?