When an air bubble at the bottom of a lake rises to the top, it will

1. An air bubble at the bottom of a lake is under higher pressure due to the weight of the water above it (hydrostatic pressure) plus atmospheric pressure. 2. As the bubble rises towards the top, the depth of the water above it decreases, resulting in a decrease in hydrostatic pressure. 3. According to Boyle's Law (assuming constant temperature, though some cooling might occur due to expansion), the volume of a gas is inversely proportional to its pressure (P₁V₁ = P₂V₂). 4. Since the pressure outside the bubble decreases as it rises, the volume of the air inside the bubble must increase to maintain equilibrium (or near equilibrium). 5. Therefore, the air bubble will increase in size as it rises.