Take about 10 mL of water each in two test tubes.
Add a drop of oil (cooking oil) to both the test tubes and label them as A and B.
To test tube B, add a few drops of soap solution.
Now shake both the test tubes vigourously for the same period of time.
Can you see the oil and water layers separately in both the test tubes immediately after you stop shaking them?
✅ Answer: No.
Leave the test tubes undisturbed for some time and observe. Does the oil layer separate out? In which test tube does this happen first?