1. Temperature describes how hot or cold an object is. Chapter 4
Grade 7 Science Unit 2
Temperature describes how hot or cold an object is.
Chapter 4

2. Discussion How does temperature affect everyday life?
What is a comfortable temperature to you? Is it different depending on the person?
How come you can feel cold inside the school sometimes but warm outside while playing hockey on the ice?

3. Mini Experiment
2 Brave Volunteers!

4. Mini-Experiment 4 Beakers!
Place one hand in a beaker of cold water 1min
Place one hand in a beaker of hot water 1min
Place your hands in the mystery temperature water
Volunteers estimate the temperature of
the water in each beaker
Measure the actual temperature with a thermometer
Were you close?

5. Mini Experiment
Why do you think there was discrepancies (differences) between their estimates and actual temperatures?

6. Discussion
We can’t just say something is ‘hot’ or ‘cold’ – because it is subjective
Scientists need a standardized way to measure temperature

7. Temperature Temperature: (general definition)
- How hot or cold something is.

8. Temperature is important everyday, everywhere!
How are you going to dress for the day?
daily temperature changes
cooking temperatures
Refrigeration temperatures
average temperatures in different geographic areas

9. Activity - predict and identify the temperature!
Cards have either an object/event or temperature
Step one: Get in groups of four. Match the temperature/object card to the correct temperature – CHECK!
Position them in order from cold to warm!

11. Standard temperatures – to know
The human body – 37ºC
Boiling point of water – 100ºC
Freezing point of water – 0ºC
Comfortable room temperature - ~21ºC

12. Review Questions: Page 119 Q’s: 1, 6, 7 & 9.

13. We need to standardize temperatures
Scientists in the past worked towards measuring temperatures and creating a standardized temperature scale.
A scale the same all over the world

14. Past Measuring Devices
1. Galileo’s Air Thermoscope:
As the air heats, the liquids drops and when cooled it rises.

15. Past Measuring Devices
2. Early Liquid Thermometer: Liquid rising up the tube shows the temperature is rising.

16. Create a Classroom Thermoscope
Page 121

17. Temperature Scales
Scales are necessary for temperatures to be accurate and comparable.
3 Types:
Fahrenheit
Celsius
Kelvin

18. Fahrenheit first widely used measuring scale for temperature
developed by Daniel Gabriel Fahrenheit

19. Celsius Scale based on the freezing and boiling points of water.
Developed by Anders Celsius

20. Kelvin
Scale starts at the coldest temperature possible - absolute zero (-273oC).
Developed by William
Thomson (Lord Kelvin)

21. Scales Comparison

22. Interactive Matching Game

24. Interactive 2 – Build your own temperature scale!

25. Measuring Devices The Liquid-in-glass Thermometer The Thermocouple
Resistance Thermometer (digital thermometers)
Bimetallic Strip (thermostat)
Infrared Thermometer (thermogram)
Bimetalic strip demo and measuring devices stations

26. The Liquid-in-glass Thermometer
Description: liquid rises as temperature increases
The lab thermometer contains colored alcohol
Use: Used in the Science lab

27. The Thermocouple Description: Made of two different metals.
Temperature change make a current that is read on a meter
Use: Measure high temperatures in a lab and in diesel engines

28. The Resistance Thermometer (digital thermometers)
Description: temperature is taken through a probe in shows up as a number
Uses: Home use but also in businesses

29. Bimetallic Strip (thermostat)
Description: Made of two different metals fused together.
These metals expand and contract causing the strip to bend when heated.
Use: In thermostats

30. Infrared Thermometer (thermogram)
Description: Shows heat as colors
Use: To show heat loss in houses or illness in bodies

31. Review Questions: Page 131 Q’s: 1, 3, 4, 6, 11 & 12.

32. Chapter Review Questions: Page 132-133 Q’s: 1, 3, 4, 6, 11 & 12.