The first law of thermodynamics can be written as an equation, Q = U + W.

A sealed cylinder contains helium gas.

The cylinder containing the helium gas is heated.

The cylinder has fixed dimensions.

(i) Which quantity increases for the helium atoms, when the cylinder is heated?

(1)

Aaverage density of the atoms

Baverage kinetic energy of the atoms

Ctotal number of atoms

Dvolume of each atom