The temperature of argon, kept in a vessel is raised by 1°C at a constant volume. The total heat supplied to the gas is a combination of translational and rotational energies. Their respective shares are

The correct option is 100% and 0%.

To understand why, we can analyze the molecular structure of argon and apply the kinetic theory of gases:

1. Molecular Structure of Argon:
Argon (Ar) is a noble gas, which means it is a monoatomic gas. It consists of single, individual atoms rather than multi-atom molecules.

2. Degrees of Freedom:
A monoatomic atom can move freely in three-dimensional space, giving it 3 translational degrees of freedom (along the x, y, and z axes).
Because a single atom is treated as a point mass, its moment of inertia about any axis is negligible. Consequently, it does not possess any rotational kinetic energy, meaning it has 0 rotational degrees of freedom.

3. Energy Distribution:
According to the law of equipartition of energy, the average energy associated with a gas at temperature T is distributed equally among all its active degrees of freedom. The energy per mole per degree of freedom is given by:

$\frac{1}{2}RT$

For argon, the total internal energy consists entirely of translational kinetic energy:

$E_{\text{translational}}=3\times \left(\frac{1}{2}RT\right)=\frac{3}{2}RT$

Meanwhile, the rotational energy is zero:

$E_{\text{rotational}}=0$

Thus, when heat is supplied at a constant volume, 100% of the energy goes into raising the translational kinetic energy of the atoms, and 0% goes into rotational energy.