1. Chapter 2 Energy and Matter
2.2 Temperature

2. Temperature Temperature
is a measure of how hot or cold an object is compared to another object
indicates that heat flows from the object with a higher temperature to the object with a lower temperature
is measured using a thermometer

3. Temperature Scales Temperature scales
are Fahrenheit, Celsius, and Kelvin
have reference points for the boiling and freezing points of water

4. Learning Check A. What is the temperature of freezing water?
1) 0 °F ) 0 °C ) 0 K
B. What is the temperature of boiling water?
1) 100 °F ) 32 °F ) 373 K
C. How many Celsius units are between the boiling and freezing points of water?
1) ) ) 273

5. Solution A. What is the temperature of freezing water? 2) 0 °C
B. What is the temperature of boiling water?
3) 373 K
C. How many Celsius units are between the boiling and freezing points of water?
1) 100

6. Fahrenheit Formula
On the Fahrenheit scale, there are 180 °F between the freezing and boiling points, and on the Celsius scale, there are 100 °C.
180 °F = 9 °F = °F
100 °C 5 °C °C
In the formula for the Fahrenheit temperature, adding 32 adjusts the zero point of water from 0 °C to 32 °F.
TF = 9 (TC) ° 5
or TF = 1.8(TC) °

7. Celsius Formula TC is obtained by rearranging the equation for TF.
TF = (TC) °
Subtract 32 from both sides.
TF – 32 ° = 1.8(TC) + (32 ° – 32 °)
TF – 32 ° = 1.8(TC)
Divide by TF – 32 ° = TC
TF – 32 ° = TC
1.8

8. Solving a Temperature Problem
A person with hypothermia has a
body temperature of 34.8 °C. What
Is that temperature in °F?
TF = 1.8(TC) °
TF = (1.8)(34.8 °C) °
exact tenth’s exact
= 62.6 ° °
= 94.6 °F
tenth’s

9. Learning Check
The normal temperature of a chickadee is °F. What is that temperature on the Celsius scale?
1) °C
2) °C
3) °C

10. Solution The normal temperature of a chickadee is 105.8 °F.
What is that temperature on the Celsius scale?
3) °C
TC = TF – 32 °
1.8
= (105.8 – 32 °)
= 73.8 °F = °C
1.8 ° tenth’s place

11. Learning Check
A pepperoni pizza is baked at 455 °F. What temperature is needed on the Celsius scale?
1) 423 °C
2) 235 °C
3) 221 °C

12. Solution
A pepperoni pizza is baked at 455 °F. What temperature is needed on the Celsius scale?
2) 235 °C
TF – 32 ° = TC
1.8
(455 – 32 °) = °C
one’s place

13. Learning Check On a cold winter day, the temperature is –15 °C.
What is that temperature in °F?
1) 19 °F
2) 59 °F
3) 5 °F

14. Solution 3) 5 °F TF = 1.8TC + 32 ° TF = 1.8(–15 °C) + 32 °
= – °
= 5 °F
one’s place
Note: Be sure to use the change sign key on your calculator to enter the minus (–) sign.
1.8 x 15 +/ – = –27

15. Kelvin Temperature Scale
The Kelvin temperature
is obtained by adding 273 to the Celsius temperature
TK = TC
In the Kelvin temperature scale:
There are 100 units between the freezing and boiling points of water.
100 K = 100 °C or 1 K = 1 °C
0 K (absolute zero) is the lowest possible temperature.
0 K = –273 °C

16. Temperatures

17. Learning Check What is normal body temperature of 37 °C in kelvins?

18. Solution What is normal body temperature of 37 °C in kelvins? 2) 310 K
TK = TC + 273
= 37 °C + 273
= 310. K
one’s place