Which of the following is a strong dehydrating agent?

Which of the following metals is relatively light in weight?

Which of the following is $NOT$ the correct order of reactivity of metals?

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:

Define an alloy. How is an alloy prepared?

Give reasons for the following:
$(i)$ Most metals conduct electricity well.
$(ii)$ The reaction of iron $(III)$ oxide,$Fe_{2}O_{3}$,with heated aluminium is used to join cracked machine parts.
$(iii)$ Sodium,potassium,and lithium are stored under oil.