Which of the following property of a small drop of mercury can be used to explain the spherical shape of mercury droplets?

At the same temperature and pressure,the rate of diffusion of gas $X$ is $3 \sqrt{3}$ times that of a gaseous hydrocarbon of molar mass $54 \ g \ mol^{-1}$. The molar mass of $X$ in $g \ mol^{-1}$ is

$A$ bulb contains $1 \ g$ of $H_2$ and $1 \ g$ of $He$. If the total pressure is $1.2 \times 10^3 \ Pa$,then the partial pressure of $He$ is ............. $Pa$.

Which state of matter has a definite volume but no definite shape?

At $100\,^oC$ and $1\, atm$ pressure,the density of liquid water is $1.0\, g\, cm^{-3}$ and the density of water vapor is $0.0006\, g\, cm^{-3}$. What is the volume occupied by water molecules in $1\, L$ of steam at the same temperature in $cm^3$?

Deep sea divers use a mixture of which gases for respiration?