When equal volumes of helium and neon at same temperature and pressure are mixed,the ratio $C_p: C_V$ of the mixture equals

Match gases under specified conditions listed in Column-$I$ with their properties/laws in Column-$II$.

Column-$I$	Column-$II$
$A$. Hydrogen gas $(P=200 \ atm, T=273 \ K)$	$p$. Compressibility factor $Z \neq 1$
$B$. Hydrogen gas $(P \approx 0, T=273 \ K)$	$q$. Attractive forces are dominant
$C$. $CO_2$ $(P=1 \ atm, T=273 \ K)$	$r$. $PV=nRT$
$D$. Real gas with very large molar volume	$s$. $P(V_m-b)=RT$

Identify the correct statements from the following.
$I$. Glass is an extremely viscous liquid.
$II$. Increase in temperature decreases the surface tension of liquids.
$III$. Compressibility factor for an ideal gas is zero.

When the temperature is raised,the viscosity of liquid decreases,this is because

During winter,when taking a bath,water vapour appears. Explain the physical process.

The rate of diffusion of $H_2$ is .......