How Does Soap Work?


I stumbled upon this piece yesterday, and just had to share it. The conversation: a (chemistry professor) father explains to his 3 year old daughter how surfactants work.

SARAH: Daddy, were you in the shower?
DAD: Yes, I was in the shower.
SARAH: Why?
DAD: I was dirty. The shower gets me clean.
SARAH: Why?
DAD: Why does the shower get me clean?
SARAH: Yes.
DAD: Because the water washes the dirt away when I use soap.
SARAH: Why?
DAD: Why do I use soap?
SARAH: Yes.
DAD: Because the soap grabs the dirt and lets the water wash it off.
SARAH: Why?
DAD: Why does the soap grab the dirt?
SARAH: Yes.
DAD: Because soap is a surfactant.
SARAH: Why?
DAD: Why is soap a surfactant?
SARAH: Yes.
DAD: That is an EXCELLENT question. Soap is a surfactant because it forms water-soluble micelles that trap the otherwise insoluble dirt and oil particles.
SARAH: Why?

Please visit the Science Creative Quarterly to read the rest of this entertaining and educating conversation.

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