Question

why the bubbles create when we heat up the water ​

Answer 1

When water is boiled, the heat energy is transferred to the molecules of water, which begin to move more quickly. Eventually, the molecules have too much energy to stay connected as a liquid. When this occurs, they form gaseous molecules of water vapor, which float to the surface as bubbles and travel into the air.

Answer 2

when water is heated the lower layer become steam gets direct heat and the upper layer is still a water

the bubbles seen is steam bubbles only!!!

hope this will help

happy learning^_^