1. The problem statement, all variables and given/known data An air bubble of volume 20 cm^3 is at the bottom of a lake 40 m deep, where the temperature is 4.0°C. The bubble rises to the surface, which is at a temperature of 20°C. Take the temperature of the bubble’s air to be the same as that of the surrounding water. Just as the bubble reaches the surface, what is its volume? 2. Relevant equations [itex]PV=kT[/itex] [itex]ΔP=40ρg[/itex] 3. The attempt at a solution I don't understand how the answer doesn't depend on the atmospheric pressure. If the atmospheric pressure were greater, then wouldn't the change in volume be smaller?