Layered Liquids!

Lesson Plan - Get It!

Audio:

So far in this Weights and Volume series, you have learned a lot about weight, volume, and their effects on other substances.

In the previous Related Lesson, found in the right-hand sidebar, you covered two main points: how weight (or density) affects certain liquids' abilities to mix with one another and how you can measure weight in grams.

• Do you remember what density is?

Density is how tightly-compacted something is. A rock is heavier than a same-size ping poing ball because the ball is not as compact as the rock; it is mostly loose air molecules.

In the previous lesson, you also learned how to measure weight in grams by using a graduated cylinder.

In this lesson, you will be measuring more items in grams. However, if you do not have a graduated cylinder, you can measure milliliters by converting teaspoons into milliliters.

• Do you remember the conversion rate of teaspoons to milliliters from the previous lesson?

It is provided below for you to use:

• 1 teaspoon = approx. 5 milliliters (mLs)
• ½ teaspoon = approx. 2.5 milliliters (mLs)
• ¼ teaspoon = approx. 1.25 milliliters (mLs)
• ¹⁄₈ teaspoon = approx. .75 milliliters (mLs)

Also, if you do not have a test tube, use a small jar or container.

There are 5 (five) items used in this lesson's experiment in order to see which is the most dense (will sink to the bottom) and which is the least dense (will float on top). These items include oil, syrup, colored water, a piece of peppercorn, and a piece of plastic.

• Which do you think will be the most dense, and why?
• Which do you think will be the least dense, and why?

Drop in on Dr. Z to find out!

• Were your predictions correct?
• Did you guess that the syrup would sink to the bottom, and that the plastic would float on the top — even on top of the oil?

This is because the syrup was the most dense item, and the plastic was the least dense item.

• Did anything that you learned in the lesson surprise you?

You can form layered liquids all because of density!

• Can you think of any ways that density is relevant to real life?

Try to think up five examples of density at work in the world, and continue on to the Got It? section for more examples.