M is for Mixtures

The A to Z Science series for toddlers and preschoolers at Inspiration Laboratories continues with the letter M. M is for mixtures.

Mixtures

A mixture has two or more different substances in it. The substances are mixed together, but are not chemically combined. You can still physically separate the two substances. Saltwater is a mixture. It contains salt and water. You can evaporate the water and the salt will remain. Some types of rocks are mixtures – they are made up of different types of rock. Even a salad is a mixture of different vegetables.

A Mixture Experiment with Oil and Water

Oil and water is considered a mixture, but they easily separate do to density differences and their chemical properties. Add an emulsifier to help oil and water mix. We experimented with different substances from the kitchen to see which ones make good emulsifiers.

Here’s what we tried:

• baking soda
• egg yolk
• dish soap
• flour
• Italian seasoning
• mustard powder
• pepper
• salt
• sugar

Other materials you’ll need:

• clear containers {graduated cylinders, test, tubes, skinny glasses…}
• oil {inexpensive cooking oil or whatever you have on hand}
• water
• spoon or stirring instrument {we used a chopstick}

Instructions

1. Add water and oil to a clear container. We used graduated cylinders because you can use less oil to see the results. Test tubes or skinny containers would work well, too.
2. Try stirring the oil and water to mix them together. You’ll notice they try to immediately separate.
3. Add one of your test ingredients to the container and stir.
4. Observe what happens. Does the oil and water mix easily? How long do they stay mixed?
5. Repeat steps 1-4 for all of your test ingredients.

You’ll notice some of the tested ingredients allow the oil and water to mix while you’re stirring, but when you stop stirring they separate again. Other ingredients {like the mustard powder shown below} will allow the oil and water to mix quite well. Eventually the oil and water might separate.

Mustard powder, egg yolk, and dish soap are all touted as great emulsifiers. This is why you’ll find mustard powder or egg yolk in salad dressing recipes. They help the salad dressing mix together. The chemical properties of soap allow it to interact with oil and water causing the mixture to be more stable.

Here’s a video of Aiden showing you how pepper and dish soap behave when added to oil and water. Notice the difference between the two.

A to Z Science for Toddlers and Preschoolers

You’ll find this activity along with 25 others in my ebook, A to Z Science for Toddlers and Preschoolers. It’s currently available as part of a limited time bundle offer. The MEGA Back to School Bundle includes $360 value worth of resources for only $24.95. You get over 50 ebooks (including my A to Z Science) and printable resource packs for 93% off in our special back to school sale only until September 1, 2017. Click here to learn more about the special offer.