Which metal is available in the highest proportion on the earth's crust?

What is the molecular formula of phosphoric acid?

$(a)$ Why does calcium start floating when added to water?
$(b)$ Most metals do not release hydrogen gas when reacting with nitric acid. Why?
$(c)$ Write the chemical equation for the reaction of iron with steam. Name the compound of iron obtained.

Which of the following metals exist in their native state in nature?
$(i)$ $Au$
$(ii)$ $Cu$
$(iii)$ $Ag$
$(iv)$ $Fe$

In the $Hall-Heroult$ process,which substances are added to alumina to lower its melting point?

Pavan separates some materials into two groups and notes their properties. These properties are given in the table below:

Group $1$	Group $2$
They cannot be beaten into sheets.	They can be beaten into sheets.
When one end is in contact with a hot object,the other end does not get hot quickly.	When one end is in contact with a hot object,the other end gets hot quickly.
They cannot be drawn into thin wires.	They can be drawn into thin wires.

Which of the following statements cannot be false?