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# 3.3: Activities and Answer Keys

Difficulty Level: At Grade Created by: CK-12

## Activity 2-1: Calories: In a Nutshell

### PLAN

Summary Students investigate the relationship between food and heat energy. They measure heat energy (in units called calories or “Cal”) released by food (a burning peanut) using a calorimeter.

Objectives

Students:

\begin{align*}\checkmark\end{align*} define heat energy and calorie.

\begin{align*}\checkmark\end{align*} determine the relationship between food and calories.

Student Materials

• Goggles; Test tube; Test-tube holder; Calorimeter (a can adapted for this purpose); Thermometer; Graduated cylinder; Cork; Needle; Matches; Peanuts
• Data Sheet
• Resource
• Activity Report

Teacher Materials

• Resources on heat energy, nutrition

Collect 8- and 16-ounce cans. Make calorimeters by first removing the top of an aluminum can. The n punch a one-half inch hole in the center of the bottom of the can. Cut 2 notches along the other end of the can for air circulation. (See the Resource.)

Gather and organize student materials listed.

Estimated Time One 50-minute class period

Interdisciplinary Connections

Math Students calculate averages and percents and practice making and using data tables.

Physical Education Relate the calories in food to fuel needed for a young person's (ages 11-15) daily activities. Compare the energy required for different sports and physical activities.

Prerequisites and Background Information

The amount of heat energy released by food is expressed in units called calories. One calorie (cal) is the amount of heat needed to raise the temperature of 1 gram (milliliter) of water by one degree Celsius. The number of calories is found by multiplying the mass of water in grams by the change in temperature in degrees Celsius. The equation is

Calories = Water (grams) times(x) Change in Temperature (degrees celsius)

We are more familiar with food calories, abbreviated with a capital C (Cal or kilocalories). The food calorie is a bigger unit of measurement than the calorie abbreviated with the small c. One calorie (Cal) is equal to one thousand calories (Cal). In equation form, if we burn a peanut and it heats 50 grams of water from 20 degrees Celsius to 50 degrees Celsius, then we are measuring 1,500 calories or 1.5 Calories (Cal).

A calorimeter is often used to determine the number of calories (Cal), or the energy in a given food item. It measures the amount of heat energy released when a food item is burned. When using a calorimeter, a person measures the temperature of water in the calorimeter before and after burning a food item. Heat energy released during this burning is absorbed by the calorimeter's water. The change in water temperature is then used to calculate the amount of heat energy released by the food.

Extend Activity 2-1 by having students conduct this activity using potato chips, both regular and reduced calorie chips. Students can design this investigation.

### IMPLEMENT

Introduce Activity 2-1 by reviewing the safety rules for lab experiments. CAUTION students to wear goggles in all experimental laboratory situations. Make sure you are wearing goggles when working with fire as a model for students. Also, caution students to be very careful with the matches and the flame in this activity.

Steps 1-7 Set up the calorimeter. Then demonstrate how to carefully place the peanut on the needle. Review how to read a thermometer.

Steps 8-9 Ask students why it is important to get 3 peanuts similar in size. Allow time at the end of the period to assist with calculations and discuss the lab results.

• It is possible to do this experiment without a calorimeter. If no calorimeter is used, some heat will be lost into the air, and the temperature difference observed will not be as great as it would be if a calorimeter is used.
• Weigh the peanuts to ensure that the three being used are similar in size.
• The average peanut half has approximately 1-3 calories.
• Provide cool, unheated, and clean test tubes for each peanut test to keep the starting temperature the same.

### ASSESS

Use the completion of the experiment and written responses on the Activity Report to assess if students can

\begin{align*}\checkmark\end{align*} relate the terms heat energy and calorie to each other.

\begin{align*}\checkmark\end{align*} explain the importance of food in providing our bodies with energy.

\begin{align*}\checkmark\end{align*} explain the function of calorimeters.

\begin{align*}\checkmark\end{align*} explain the importance of conducting a number of trials to collect the most accurate data.

## Activity 2-1 Calories: In a Nutshell – Activity Report Answer Key

• Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.
1. Using the data collected, calculate the average number of calories (Cal) in a peanut half.
2. What function does the calorimeter serve?
3. What reason could there be for a difference in the numbers of calories (Cal) in the 3 peanut halves?
4. There are dry roasted peanuts on the market that are advertised to be lower in calories (Cal) than other peanuts. How could you test this advertising claim?
5. If a peanut half and a sugar cube weighed the same, which do you think would provide more energy when burned? Explain.
6. Approximately how many whole peanuts would you have to eat to provide your body with 1,800 calories (Cal)?

You are the advertising director for a campaign to encourage teens to exercise. What specific aspects of the lifestyles of different teenagers would you target in your campaign? What are some slogans that you would use in your advertisements? Why do you think they would be effective?

## Activity 2-2: Calories: How Much Energy Do You Use?

### PLAN

Summary Students estimate the number of calories (Cal) the body needs for a typical day. Using the Food Diary from Activity 1-1: Are You What You Eat? students compare the number of calories consumed with the calories they actually need based on age and weight.

Objectives

Students:

\begin{align*}\checkmark\end{align*} determine the average number of calories (Cal) they need in a 24-hour period.

\begin{align*}\checkmark\end{align*} compare the number of calories they eat with the number of calories they need.

Student Materials

• Data Sheet
• Activity Report

Teacher Materials

• Calorie expenditure charts and resources

Gather charts and resources that list various activities and their calorie (Cal) expenditures per unit time and RDA Chart. (See Resource, Activity 6-1.)

Estimated Time 20 minutes on the first day and 20 minutes after students collect their data

Interdisciplinary Connections

Physical Education Compare energy requirements for different sports or physical activities such as walking and running.

Math Calculate averages. Make and use data charts and tables.

Social Studies Discuss how different cultures regard physical activity. Students can compare calorie (Cal) requirements for different types of occupations.

Prerequisites and Background Information

Completion of Activity 1-1: Are You What You Eat? and Activity 2-1 : Calories: In a Nutshell.

### IMPLEMENT

Introduce Activity 2-2 by reviewing the calorie (Cal) expenditures for different physical activities.

Steps 1-2 Select a day for students to begin their 48-hour activity record. Use a chart on a transparency to fill in sample data from a student volunteer. In this way students see an example of how to estimate calories expended per hour. An alternative would be to use hypothetical data reflecting a typical pattern of activities for a middle school student. Suggest that students record activities for one weekday and one weekend day.

Step 3 There may not be 10 males and 10 females in class. However, make sure students record an equal number of males and females. For example, if there are only 8 males in the class, have students record the data for 8 males and 8 females during a 24-hour period.

• Provide lists or examples of calorie expenditures for different physical activities.
• Have students bring their Activity 1-1 Report. If not available, have them use the Resource (RDA Chart) from Activity 6-1 to determine the allowances for their gender/age.
• Assist students in estimating the calorie expenditures per hour if they have engaged in more than one type of activity.

### ASSESS

Use the completion of the Activity Data Sheet and written responses on the Activity Report to assess if students can

\begin{align*}\checkmark\end{align*} identify the average number of calories (Cal) needed in a 24-hour period.

\begin{align*}\checkmark\end{align*} compare the number of calories (Cal) they consumed with the number of calories (Cal) they need in a typical day.

\begin{align*}\checkmark\end{align*} calculate the average calorie (Cal) expenditure per day for students in the classroom.

\begin{align*}\checkmark\end{align*} compare average calorie (Cal) expenditures per day for girls with those for boys.

## Activity 2-2 Calories: How Much Energy Do You Use? – Activity Report Answer Key

• Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.
1. Calculate the average number of calories you expend in one day. Calories expended per day _______________________________
2. Are the days during which you recorded your energy use typical days for you? Are you usually more or less active?
3. Can you think of a way to obtain results that show a more accurate picture of how much energy you typically use?
4. What was your average daily calorie intake, that is, the number of calories you usually consume, as determined in the Food Diary from Activity 1-1: Are You What You Eat? _______ = average number of calories (Cal) consumed per day
5. How does your average number of calories (Cal) consumed (#4) compare with the average number of calories you used (#1)? Explain. Calories Consumed = ______ Calories Expended = ______
6. What is the average calorie (Cal) expenditure per day for 10 females in your class? Calories per day =
7. What is the average calorie (Cal) expenditure per day for 10 males in your class? Calories per day =
8. Compare the average daily energy use in calories (Cal) for males with the average daily energy use for females. What factors determine energy or calories (Cal) needed per day?

Reading Food Labels Students analyze a variety of food labels. It is important that they, as consumers, know what they are buying. Federal laws require that certain information be provided. Some manufacturers print additional information on their labels.

What Do You Think?

Why do you think it is recommended that you take the skin off chicken before you eat it?

What Do You Think?

Why do you think fruit yogurt has more calories (Cal) than plain yogurt?

A suggested response will be provided upon request. Please send an email to teachers-requests@ck12.org.

A healthy amount of fat for 11-14-year-olds to consume ranges from 65 to 85 grams per day. Suppose that in one day you eat 2 chocolate chip cookies, 4 servings of potato chips, an ice cream cone, and 2 tablespoons of mayonnaise on your sandwich. How many grams of fat have you consumed?

What Do You Think?

Considering the list of nutritional guides shown here, which do you think would be the easiest for you to follow and why? Which would be the hardest for you to follow and why?

• Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.
1. What is the relationship between a calorie (Cal), a piece of bread, and the term energy?
2. Explain why the 5 food groups are displayed in the shape of a pyramid instead of a square.
3. Design and complete a table that includes the food groups, major nutrients in each group, and examples of food in each group.

## Activity 2-1 Data Sheet: Calories: In a Nutshell (Student Reproducible)

A calorie (Cal) is the amount of heat needed to raise the temperature of 1 liter of water 1C\begin{align*}1^\circ C\end{align*}.

Trial 1 Trial 2 Trial 3
A. water volume (ml)

B. water temp. (C)\begin{align*}(^\circ C)\end{align*}:

before heating with burning peanut half

C. water temp. (C)\begin{align*}(^\circ C)\end{align*}:

after heating with burning peanut half

D. temp. increase

E. small calories (Cal) in peanut half

volume of water (ml) ×\begin{align*}\times\end{align*} temp. increase

F. big calories (Cal or kilocalories) in peanut half

(small calories/1,000)

## Activity 2-1 Report: Calories: In a Nutshell (Student Reproducible)

1. Using the data collected, calculate the average number of calories (Cal) in a peanut half.

2. What function does the calorimeter serve?

3. What reason could there be for a difference in the numbers of calories (Cal) in the 3 peanut halves?

4. There are dry roasted peanuts on the market that are advertised to be lower in calories (Cal) than other peanuts. How could you test this advertising claim?

5. If a peanut half and a sugar cube weighed the same, which do you think would provide more energy when burned? Explain.

6. Approximately how many whole peanuts would you have to eat to provide your body with 1,800 calories (Cal)?

## Activity 2-2 Data Sheet: Calories: How Much Energy Do You Use? (Student Reproducible)

Fill in the chart over 2 clays. One day should be a weekend day if possible.

Time Day 1 Day 2
Activities Calories Burned Activities Calories Burned
Noon-1 PM
1 PM-2 PM
2 PM-3 PM
3 PM-4 PM
4 PM-5 PM
5 PM-6 PM
6 PM-7 PM
7 PM-8 PM
8 PM-9 PM
9 PM-10 PM
10 PM-11 PM
11 PM-Midnight
Midnight-1 AM
1 AM-2 AM
2 AM-3 AM
3 AM-4 AM
4 AM-5 AM
5 AM-6 AM
6 AM-7 AM
7 AM-8 AM
8 AM-9 AM
9 AM-10 AM
10 AM-11 AM
11 AM-Noon

## Activity 2-2 Report: Calories: How Much Energy Do You Use? (Student Reproducible)

1. Calculate the average number of calories you expend in one day.

Calories used per day ______________________

2. Are the days during which you recorded your energy use typical days for you? Are you usually more or less active?

3. Can you think of a way to obtain results that show a more accurate picture of how much energy you typically use?

4. What was your average daily calorie intake, that is, the number of calories you usually consume, as determined in the Food Diary from Activity 1-1: Are You What You Eat?

______ = average number of calories (Cal) consumed per day

5. How does your average number of calories (Cal) consumed (#4) compare with the average number of calories you used (#1)? Explain.

Calories Consumed =______ Calories Expended =_______

6. What is the average calorie (Cal) expenditure per day for 10 females in your class?

Calories per day = ________

7. What is the average calorie (Cal) expenditure per day for 10 males in your class?

Calories per day = ________

8. Compare the average daily energy use in calories (Cal) for males with the average daily energy use for females. What factors determine energy or calories (Cal) needed per day?

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Subjects:
6 , 7 , 8
Date Created:
Sep 08, 2014