The compound that is used in smoke screens is

In $P_4O_{10}$,the number of oxygen atoms attached to each phosphorus atom is

Carbon differs from other elements of the group. Which is the false statement?

Which of the following does $NOT$ give oxygen upon heating?

Which of the following orders is not correct?

Give reasons:
$(i)$ Conc. $HNO_3$ can be transported in aluminium container.
$(ii)$ $A$ mixture of dilute $NaOH$ and aluminium pieces is used to open drain.
$(iii)$ Graphite is used as lubricant.
$(iv)$ Diamond is used as an abrasive.
$(v)$ Aluminium alloys are used to make aircraft body.
$(vi)$ Aluminium utensils should not be kept in water overnight.
$(vii)$ Aluminium wire is used to make transmission cables.