Which one of the following is not a unit of pressure?

Pressure is defined as the force acting per unit area of a surface. The $SI$ unit of pressure,$Pascal$ $(Pa)$,is defined as $1 \ Pa = 1 \ N \ m^{-2}$. If the mass of air at sea level is $1034 \ g \ cm^{-2}$,calculate the pressure in $Pascal$.

$1 \, kg \, m^{-3} = \dots \, g \, cm^{-3}$

In the equation of state of an ideal gas $PV = nRT$,the value of the universal gas constant $R$ depends only on:

Among the following,the correct statement is

If the diameter of a carbon atom is $0.15 \,nm$,calculate the number of carbon atoms which can be placed side by side in a straight line across the length of a scale of length $20 \,cm$.