Which one of the following metals does not react with cold as well as hot water?

Write the chemical equation for the reaction taking place when steam is passed over hot aluminium.

$A$ mixture of equal amounts of $H_2$ and $Cl_2$ gases in a gas jar produces white fumes in the absence of sunlight. What are these white fumes?

$A$ metal $M$ forms an oxide having the formula $M_{2}O_{3}$. It dissolves in both dilute sulphuric acid and dilute sodium hydroxide solution. Identify the metal and write the chemical equations for the reactions involved.

An element $A$ is soft and can be cut with a knife. It is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following:

What is the ratio of dihydrogen gas to dinitrogen gas used in the production of ammonia gas by Haber's process?