How to make merging and separating bubbles?

Question

Unity

In some games I saw such an effect - two bubbles touch, when you click on one of them, for example, they merge into one equal to the size of both of them, and it looks like in reality, so I don’t think that animation is involved here, the same is about separation - click and one bubble is divided into two bubbles 2 times smaller...
Give examples of this implementation, methods of how this is done, maybe links to examples...