Why Does Oil Float on Water? Density in a Jar!

What Crafty Clover says in this video

Intro

Hi! I'm Crafty Clover! Let's discover something amazing. Why does oil float on water?

The Big Idea

Pour some cooking oil into water, and it makes a golden layer, right on top! Oil and water just don't want to mix, and oil is lighter for its size. Let's find out why.

Don't Mix

Step one: oil and water do not mix well. Water molecules love to stick to each other, like best friends holding hands. Oil can't join in, so the water squeezes it out, into its own blobs and layers.

Less Dense

Step two: oil is less dense, so it rides on top. Dense means how much stuff is packed into a space. A cup of oil is lighter than a cup of water. So the heavier water sinks to the bottom, and the lighter oil floats on top!

Soap

Step three: soap can help them join, for washing. A soap molecule has two ends. One end grabs onto water, and the other end grabs onto oil. So soap wraps up greasy oil, and the water can rinse it away. That's how dishes get clean!

A Closer Look

Let's look closely at our jar! On top, the lighter oil floats. In the middle, you can see a clear line, where they meet. And at the bottom sits the heavier, denser water.

Quick Facts

Quick facts! Salad dressing separates for the same reason. That's why you shake it! Ocean oil spills float on top of the water too. Ice floats on water too, because it's less dense than liquid water. Honey is denser than water, so it sinks!

Think Like a Scientist

Now, think like a scientist! Put water and a little oil in a jar, and close the lid tight. Shake it hard, then set it down, and watch them split. Now add a drop of dish soap, and shake again. What changes?

Outro

So oil floats on water because the two don't mix, and oil is less dense, so it rides right on top! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!