Big Things Come in Little Packages A - 1 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

Big Things Come in Little

Packages

Learning Objectives: Objects that are the same volume but different weights have different densities.

SNEAK PEAK inside …

Advance Preparation Set Up Activity Clean Up

15 minutes 0 minutes 20 minutes 2 minutes

GRADE LEVEL

K–5

SCIENCE TOPICS

Physical Properties Techniques

PROCESS SKILLS

Comparing and Contrasting Measuring

Organizing Data Evaluating

GROUP SIZE

1–2

TIME REQUIRED

ACTIVITY Students learn about density by comparing gift-wrapped packages that are the same size but have different densities. STUDENT SUPPLIES small boxes, all same size coins, nails, screws, bolts, or other heavy

metal scraps wood blocks or scraps foam rubber, Styrofoam peanuts, or large

marshmallows gift wrapping paper ADVANCE PREPARATION Fill boxes with different materials and wrap. OPTIONAL EXTRAS EXTENSIONS Twenty Questions (p. A - 6) Determining Volume (p. A - 6) Determining Density (p. A - 7)

Big Things Come in Little Packages A - 2 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

Item Amount Needed

small boxes of the same size (approx. 4-inch cubes) 3 per class coins, nails, screws, bolts, or other heavy metal scraps enough to fill box wooden block or scraps of wood enough to fill box foam rubber, Styrofoam peanuts, or large marshmallows enough to fill box

gift wrapping paper and tape enough to cover each box

For Extension or Demonstration supplies, see the corresponding section.

Supplies Preparation Boxes:

Make sure that all three boxes are the same size and shape. (A cut-down half-gallon milk carton works well as a box.)

Fill one box as full as possible with heavy metal scraps, nuts, bolts, screws, etc.

Fill a second box as full as possible with a block of wood or scraps of wood.

Fill the third box (without making the box bulge) with foam rubber, Styrofoam peanuts, or large marshmallows.

Gift wrap the three boxes. You can wrap the three boxes identically or wrap them differently so that the students will have an additional criterion for comparing the three boxes.

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ADVANCE PREPARATION

SUPPLIES

SETUP

Big Things Come in Little Packages A - 3 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

In this acitivity, students will have the opportunity to compare gift-wrapped packages that are the same size but different densities. Have the class look at (but not touch!) the three gift-wrapped boxes. By not allowing the students to touch or feel the boxes, you will limit the information they can gather and also increase their curiosity. Atoms and molecules are also impossible to touch and feel directly, yet scientists are still curious about them. Scientists use the properties of materials to learn about the atoms and molecules inside them.

What is alike about the packages? They are the same size or volume, they take up the same amount of space, they are all boxes, and they are all wrapped as gifts.

What might be different about the packages? They could be different weights, different values, filled to a different degree, etc. It’s hard to tell by just looking.

Without having the students lift or touch the boxes, ask:

Which box do you think is heaviest? You can make a bar graph of student responses: Column one = number of students who think box 1 is heaviest.

Column two = number of students who think box 2 is heaviest.

Column three = number of students who think box 3 is heaviest.

Column four = number of students who think all boxes weigh the same.

Have the students hypothesize what is in the packages. This will not be a very informed hypothesis because they have very little information. The only clue they have is package size.

INTRODUCING THE ACTIVITY

Let the students speculate before offering answers to any questions. The answers at right are provided for the teacher. Choose questions that are appropriate for your classroom.

Big Things Come in Little Packages A - 4 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

This activity does not have a Scientific Procedure. Instead, lead the activity according to the directions below. NOTES

One of the best ways to find out what’s inside the box is to measure as many things as possible about the box, such as the weight, size, shape, color, etc. Here is a fun way to demonstrate the different weights of the boxes to the class.

1. Have three volunteers come forward (preferably including one very small student and one very large and apparently strong student).

2. Give the lightest weight package (the foam or marshmallows) to the smallest volunteer. Give the heaviest package (metal) to a strong volunteer.

3. Ask the three students to do arm lifts with their package. If the packages are on the small side, the students may need to extend their arms to experience the weight difference as they do arm lifts.

4. Ask the class to count the number of arm lifts each student can do with the package over a period of time (about 1 minute). Compare the number of arm lifts for each package.

5. Ask the volunteers how difficult the task was. Compare their answers.

6. Ask the class: What might be different about the packages? Which box is heaviest? (You can make another bar graph of student responses.) Ask the class: Who changed their minds about which package is heaviest? On what did you base your decision?

7. If it is still not clear which package is heaviest, give several (or all) students the opportunity to lift each of the packages and compare.

8. Have students hypothesize again what is in the various packages. They have more information, or data, now. When scientists make a hypothesis, they base it on all the information they have.

9. Now have three volunteers unwrap the package and inspect the contents. They can show the class, or play “20 questions” with the class, allowing the class to gather more information by asking questions.

CLASSROOM ACTIVITY

Big Things Come in Little Packages A - 5 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

Scientists use density to describe how heavy something is compared to its size. Objects that are the same size but different weights have different densities. Which box is heaviest: the one with metal, foam, or wood? metal Which is lightest? foam Density is mass (similar to weight) divided by volume (size). When two things are the same size, the heavier one is more dense. Which box is least dense? foam Can you think of some very dense objects? metal objects, rocks, etc. Can you think of some objects that are not very dense? balloons, marshmallows, pillows, an empty box, etc.

Scientists study objects by learning about their properties. Color, size, and shape are all properties that allow scientists to study what objects look like. In this activity, students learn that even when things look alike, there are still other properties that allow them to tell objects apart. The Matter Around Us All matter is made of atoms. Atoms combine to make molecules. Atoms and molecules are too small to see, but, together, they make up all stubstances. To find out how much matter is in a substance, scientists weigh the substance to find its mass. The more matter an object has, the more mass it has. Density In this activity, students study three objects that all have the same volume, that is they each take up the same amount of space. The three boxes all look the same, but students find out that they all have a different amount of mass; they each weigh a different amount. When scientists compare an object’s mass to its volume, they call this property the density of the object.

CLASSROOM DISCUSSION

EXPLANATION

Ask for student observations and explanations. Let the students guide the discussion and present their hypotheses before discussing explanations. Choose questions that are appropriate for your classroom.

Big Things Come in Little Packages A - 6 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

The lightweight package contained foam, Styrofoam, or marshmallows. In these substances, the atoms and molecules are not packed together very tightly. There is not very much matter packed into the space. For this reason, the package has the least mass and is the least dense. The metal-filled box was the most dense because the atoms in metals tend to be packed very tightly. Each particular type of metal has its own density; for example, lead is much denser than aluminum. The atoms in lead are larger and more tightly packed than the atoms in aluminum. Sink or Float? The concept of density explains why things sink or float in water. If a solid (like wood) is less dense than water, it will float on the water—regardless of its weight. For instance, pianos float on water, even though they are very heavy, because they are made of wood, which is less dense than water. On the other hand, solids that are more dense (like metals) will sink in water. Even a piece of metal as light as a dime will sink in water, because the metal is more dense. For more examples and discussion about density, see the Explanation section in the activity Density Rainbow. Extension A: Twenty Questions Have the students bring in gift-wrapped boxes. Let other students hypothesize what is in them. Let other students lift the packages. They can play 20 questions with each owner. Extension B: Determine Volume (Grades 3–5) Students determine the volume of the three boxes. Extra Supplies

ruler ( inch or centimeter) Extra Instructions

Measure the width, length, and height of the boxes. (Be sure to use the same units for each measurement.)

Determine the volume by using the following equation:

volume = width x length x height

If students measured the dimensions in inches, then the volume is measured in cubic inches. If students measured the dimensions in centimeters, then the volume is measured in cubic centimeters.

EXTENSIONS

Big Things Come in Little Packages A - 7 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

Extension C: Determining Density (Grades 4–5) Students determine the density of each box. Extra Supplies

rulers (inch or centimeter) scale (ounces or grams)

Extra Instructions

Find the mass of each box. Determine the volume of each box (See Extension B above). If your scale is

in ounces, it is best to measure in inches. If your scale is in grams, it is best to measure in centimeters.

Determine the density using the following equation:

volumemassdensity =

The result should be in either pounds per cubic inch or grams per cubic

centimeter. FORENSIC SCIENCE

Counterfeit Coins and Jewelry Research how law enforcement can use density to detect counterfeit coins and jewelry.

MATHEMATICS Density of Other Objects

Extensions B and C require multiplication and division, respectively. You can further develop this by having students measure and weigh other objects to determine their volumes and densities.

LANGUAGE ARTS Mystery Object

Have the students write a story about a mystery package. Have them reveal clues using descriptive language.

ECOLOGY Density of Ice versus Water

Ice is less dense than water, which is why it floats. Write about how the world would be different if solid water was more dense than liquid water. (Oceans and lakes freezing from the bottom up, etc.)

CROSS-CURRICULAR CONNECTIONS

Big Things Come in Little Packages A - 8 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

Great Explorations in Math and Science (GEMS), Discovering Density, Lawrence Hall of Science Target level: 6th to 10th grade This teachers’ manual includes five 25- to 50-minute lessons and possible follow-up lessons. Each activity is well designed, includes detailed instructions, handouts, and data tables. atoms: a very, very small particle that makes up all matter density: describes how tightly packed matter (molecules, people) is

in a space; dense is the adjective, density is the noun mass: the amount of matter in an object or substance; measured

by weight matter: anything that has mass and occupies space; stuff molecule: a group of at least two atoms held together in a definite

arrangement volume: the amount of space filled by an object or substance

RESOURCES

VOCABULARY

Big Things Come in Little Packages A - 9 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI

This worksheet is available online at www.omsi.edu/k8chemistry.

Big Things Come in Little Packages Recommended group size: whole class

Number of Students: Number of Groups:

Supplies Amount Needed Supplies on Hand

Supplies Needed

small boxes of the same size (approx. 4-inch cubes) 3 per class

coins, nails, screws, bolts, or other heavy metal scraps enough to fill box

wooden block or scraps of wood enough to fill box foam rubber, Styrofoam peanuts, or large marshmallows enough to fill box

gift wrapping paper and tape enough to cover each box

Extension A No additional materials needed

Extension B rulers 1 per group

Extension C rulers 1 per group scale 1 or more for class to share

SUPPLY WORKSHEET

Big Things Come in Little Packages A - 10 Chemistry in the K–8 Classroom Grades K–5 2007, OMSI