Use MatchCard Science density worksheet to teach the density formula.

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MatchCard:

MatchCard Information Pieces are used to create the density formula (mass divided by volume) and identify which objects have greater density.

Projects: Given a set of irregular objects, students arrange them by their estimates of most to least dense. Calculate the density of the objects using a scale and water displacement. Learn a mnemonic for the density formula.

This is **MatchCard #10** of the Chemistry Unit Study. Find more information on MatchCard Science below.

**
Density equals Mass divided by Volume
Mass
___________
Volume**

For instance, you could have a small rock, gold ring, or quarter for the little object with greater density. Then you might use a large bouncing ball or plastic dinner plate as the larger item with less density.

Ask the students which item has greater mass. The answer should be the larger item.

Then ask which would have greater mass if they both were the same size. The answer would be the smaller item.

Then ask: "How can we compare the mass of these two objects of different sizes?"

Give the student time to think about and compose the answer to this question.

So what two things do we need to determine density?

- Mass
- Volume

- Different coins
- Several small or medium rocks
- Marble, lego, small toys
- Key
- Paper clip

Write it down, so they can compare it later.

Mass is determined by a scientific scale. If you don't have a scientific scale, you can use a small scale like a postal or diet scale to measure weight. You do want to use metric so convert to grams.

If you do not have an accurate enough scale, you may need to measure a number of items. For instance, when measuring the density of pennies, it helps to get the mass and volume of four or five pennies rather than just one, unless you have a scientific scale with precision for tenths of grams.

Let them try to figure out how they might measure volume of irregularly shaped items.

You may be able to measure by dropping the object into a beaker or cylinder and determining how much the volume in the container increases by milileters.

The best way is to use water displacement. It would be great if you happened to have a water displacement measurer. But in the very likely case you do not have one, here is how to make one:

- Puncture a hole in a disposable or Styrofoam cup.
- Place the cup inside a measuring cup that has metric measurements (usually milliliters).
- Fill the cup to the level of the hole.
- Drop the object into the cup. It will displace the volume of the object so that the same volume of water spills out of the hole and into the measuring cup.
- Measure the volume of water in the cup.

Liquid volume of milliliters (ml) can be converted to solid volume of cubic centimeters (cc).

Now compare the list of actual densities to their list of estimates before the activity. How close were they?

First, write down the density formula using only the first letter of the three words. It would be D = M/V. (Don't make the division sign at a slant but straight across, parallel to the bottom of the paper.)

The "D" stands for "dearly" or "dear." Then draw the M and V to look like a heart.

The "M" forms the top of the heart. Draw it so it looks like the famous golden arches of a fast food restaurant.

Then draw the "V" as the bottom of the heart.

Now you have the density formula in a picture they will never forget!

MatchCards make science concepts and corresponding vocabulary interactive. As students move the information pieces on the MatchCards they review the material they have already learned.

Download the FREE MatchCard Science Instructor's Guide and see how MatchCards can make building their science knowledge base fun.

Kids learn about the atoms and molecules that make up our planet and the different chemical reactions that occur every day.

Explore the building blocks of matter with the chemistry unit study.

Chemistry is only one of twelve complete unit studies for kids in 3rd to 8th grade.

Comprehensive objectives, hands-on projects, suggested science fair experiments, and the fun game-like MatchCards keep them interested in learning science. See all twelve MatchCard Science Unit Studies.

By Karen Newell Copyright© 2009 - 2020 Learn For Your Life All Rights Reserved