Explanation: \(\text{Hints: } E = \frac{3}{2}nRT\) \(\text{Solve: } R = 8.31 \, \mathrm{Jmol^{-1}K^{-1}}, \, T = 30^\circ \mathrm{C} = 303 \, \mathrm{K}\) \(n = \frac{4}{28} = 0.143 \, \mathrm{mol}\) \(E = \frac{3}{2}nRT = \frac{3}{2} \times 0.143 \times 8.31 \times 303 = 540 \, \mathrm{J}\) \(\text{Ans. (E)}\)