Outreach 2014

 

CANDAC Outreach

Title: Homemade Thermometers

Grade Level: Elementary

Subject: Science and Technology

Duration and frequency of activity: 60 minutes


 

Lesson at a glance

Students use simple materials to make a homemade thermometer.

Focus question(s)

What is temperature? How do thermometers work? Is it possible to make a homemade thermometer?

Background

Temperature is the relative hotness or coldness that can be measured using a thermometer. It is also a measure of how fast the atoms and molecules of a substance are moving. Temperature is measured in degrees on the Fahrenheit, Celsius, and Kelvin scales, but we mainly use degrees Celsius to measure temperature in Canada. Homemade thermometer explanation: When the air inside the bottle expands, the pressure inside the bottle increases, pushing down on the liquid inside the bottle and pushing more liquid up the straw. When you cool the air again, it loses energy and decreases the pressure. The coloured water will then be pushed back down the straw by the pressure of the air outside.

Instructions

 



 

1. Prior to class, set up four stations with bowls of different temperature water. Label the stations A, B, C, and D.

2. Use a kinaesthetic activity to demonstrate temperatures changes of the atmosphere. Have students stand up and slowly sway a tiny bit from side to side. Tell students that all substances (including air) are made up of tiny particles called atoms and molecules; tell students that they are gas molecules in the atmosphere (or air). When the gases in the atmosphere are moving slowly, the temperature is very cold. Ask students to move a little bit faster and tell students that as the gases in the atmosphere gain energy they move faster and the temperature raises. Ask students to move even faster and tell students that as more energy is added to the atmosphere, the temperature gets warmer and warmer! Say FREEZE to end the activity and ask students to sit down. Review the concept by asking students to explain temperature in terms of energy and molecules.

3. Guide students through the instructions for making a homemade thermometer.

a) Add mixture of half isopropyl alcohol and half water to fill 1/4 of each bottle. Add a drop of food colouring to each bottle.

b) Roll the modeling clay into a ball.

c) Flatten the ball so that it is about the same size as the bottle lid.

d) Poke a hole in the center of the modeling clay using a pencil crayon.

e) Insert a straw into the hole in the modeling clay.

f) Put the straw and modeling clay lid into the bottle.

g) Level the straw so that the bottom is in the liquid but not touching the bottom.

h) Press the modeling clay around the straw and bottle to ensure a tight seal.

i) Your thermometer is finished!

4. Ask students to gently hold the bottom of the bottle and watch what happens inside the straw. Ask students to explain what is happening and why.

5. Ask students what would happen if they removed their hands from the bottle and why.

6. Split students into four groups and have them rotate through the stations testing their homemade thermometers in the different temperature water.

7. As a class, determine the relative temperatures of the stations from coldest to hottest. Write the order on the board.

8. Use a real thermometer to confirm your classes’ temperature order.  Write the actual temperatures beside the station letters on the board.

9. Ask students to help clean up.

Materials

· Food coloring

· Rubbing alcohol

· Clear, narrow-necked plastic bottles (1per student)

· Clear plastic drinking straws (1 per student)

· Modeling clay (1 ball per student)

· Pencils (for poking hole in modeling clay)

· Water of various temperatures (i.e. ice, cold, warm , and hot)

· Station labels A, B, C and D

· Paper towlels or small towels

Instructional method

· Kinesthetic activity

· Oral questioning

· Hands-on demonstration

Assessment

 

Demonstrates an understanding of temperature and how a thermometer works.

Participation in thermometer activity and discussion.

Helpful links

Use the article found at http://www.sciencedaily.com/releases/2012/01/120119152353.htm to discuss global average temperature.

Extension/adaptations

Have students mark a scale for their thermometer. Either let students figure out how to mark a scale or give them instructions. They will need a real thermometer to do this. Instructions: Place a commercial thermometer next to your homemade one. Draw a line on the white card next to the water level in the straw. On this line, write the temperature you read on the commercial thermometer. Take the two thermomters to colder and warmer places, and record the commercial thermometer readings next to the water levels on your homemade scale. The more temperatures you record, the more exact your thermometer will be.

Source

University of Western Ontario: “Make your Own Thermometer!” Retrieved March 3, 2011 <http://publish.uwo.ca/~cagis/experiments/thermo.htm>.