Question

when water containing washing powder is stirred vigorously, the foam floats above water .why?

Answer 1

When water containing washing powder is stirred vigorously, white colored bubbles or foams are formed in huge quantity.

These bubbles are commonly known as the lather.

The lather or the bubbles have a lesser density than water.

So, being less dense, the bubble or lather or foam gets separated from the water and floats above it.