Why does olive oil float on water

The negative end can bond to the positive end of another forming a third bond, which creates a tetrahedral crystal structure. Because of the size and shape of the water molecule, this structure takes up more space than freely jostling water molecules in the warmer liquid state, and so ice floats.

Silicon, gallium, germanium, bismuth, antimony and other polar molecules also form tetrahedral crystals which float when submerged in their warmer, liquid form, but you won't or at least, shouldn't find any of those in their liquid form to put in your fridge. It's a good thing most substances shrink when they freeze, by the way.

If they didn't, things like injection moulding would be impossible, and that's just for starters. It's also a good thing that water expands when it freezes because if it didn't, lakes in cold climates would freeze solid in winter, wiping out all the critters that have a crack at living inside them.

It's not so great, however, when someone forgets about a bottle of champagne or beer in the freezer. There's a good chance the bottle will crack or explode when the water inside freezes and expands.

Mountains erode for the same reason because the water freezes between the cracks in a rock creates enough pressure to split them in half. So there you have it. Ice floats, frozen olive oil sinks and that should be more than enough to keep you smiling while you're chewing your olives and sipping a cold drink this summer!

Tags: science , chemistry. Email ABC Science. By clicking 'Send to a friend' you agree ABC Online is not responsible for the content contained in your email message. Despite being as 'Aussie as', Ruben Meerman was actually born in Holland. He moved to Bundaberg, Queensland when he was 9 and started surfing a few years later.

He decided to study physics at school in an attempt to sit next to a hot girl. Sadly, this didn't work but it was the beginning of another beautiful relationship…with science! Read more». On the other hand, an emulsifier like tomato paste has protein molecules that more or less coat the oil droplets and prevent them from bonding together, keeping them relatively well dispersed in the water.

While it gets there differently, when well mixed, the end result is about the same. So, when making a typical dressing, you first mix together the emulsifier or emulsifiers and the vinegar, and then slowly add a thin stream of oil while whisking or blending vigorously and constantly.

Between the thin stream and determined whisking, the oil will be broken into tiny drops and dispersed; and, since the emulsifier is there to either coat the oil or bind it to the vinegar, it will remain suspended in the mixture for a good deal of time. Your email address will not be published. Watch carefully! Now for the really neat part!

Step 4: Use a salt shaker to pour salt over the mixture. Watch the oil fall and rise. Continue adding salt to keep the movement going. What is happening? Salt is more dense heavier than oil or water so it is going to sink. As the salt sinks it pulls blobs of oil down with it. When the salt starts to dissolve, it releases the oil. The oil rises back to the surface. You get dancing oil! Learn more about the density of oil in the next experiment.

Make a Rainbow in a Jar. After 10 minutes have passed look at the contents of the bottles and note the changes. What does the oil and water look like in each bottle? Has the oil mixed with the water, sink to the bottom or rise to the top?

Extra: Add food coloring to the water to get a lava lamp effect Extra: Test other types of soap, such as toothpaste, hand soap and shampoo by mixing them with oil and water. Build a Cooler. Get smart. Sign up for our email newsletter. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber?

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