Why do vapor bubbles in a pot of boiling water increase in size as they rise in the water?
Solution 26E Step 1: Bubble is nothing but vapour formed as a part of boiling. So, this will be a point like structure when it is formed at the bottom of the pot. Since it is having lower density than the liquid water, it will move from the bottom of the pot to the top. The pressure of the water column will decrease as we move up. So, the pressure on the bubble will decrease as it travels from bottom to top. As the pressure decreases, the size of the bubble will increase and it will grow. But if it reaches the top, the high air pressure outside the bubble will break it up. One more possibility is there behind this phenomenon. Once a bubble is created at the bottom of the pot, it will grow as big by joining with another tiny bubbles as it travels up. Conclusion: Two factors behind this phenomenon are, the decrease in pressure of the water column from bottom to top and the joining of tiny air bubbles.