A spherical air bubble in a lake expands as it rises slowly to the surface. At the point it starts to rise, the pressure is \(2.00 \mathrm{~atm}\), the temperature of the water is \(10.0^{\circ} \mathrm{C}\), and the radius of the bubble is \(5.00 \times 10^{-3} \mathrm{~m}\). At the surface, the pressure is \(1.00 \mathrm{~atm}\) and the temperature of the water is \(20.0^{\circ} \mathrm{C}\).

(a) What is the final-to-initial volume ratio for the expanding bubble?

(b) What is the change in thermal energy of the bubble?