Celsius and Farhenheit
Objective: Compare celsius and fahrenheit.
A simple starting point in comparing celsius and fahrenheit scales is to have the student take their temperature. If you have a thermometer that registers in both celsius and fahrenheit, check both.
Explain that the average
temperature for humans is 98.6 F or 37.0 C.
To gain practice using both, check daily climate temperatures in both fahrenheit and celsius scales. Have them estimate the temperatures before checking them.
Boiling Point of Water
Here is an experiment to check the boiling point of water. It works best if you have a thermometer that measures both. You could also use two seperate thermometers.
- Fill a pan 3/4 full of water.
- Put the thermometer(s) in the water.
- Turn the stove top on.
- Observe the temperature as it rises on the thermometer.
- Note the boiling point of water.
Students should realize that the boiling point of water is 212 degrees F or 100 degrees celsius. Point this out on the Celsius to Fahrenheit Matchcard.
Compare that with the fact that the human body temperature is 98.6 degrees F. Consider how confusing it would be if you mixed up the two scales.
Freezing Point of Water
It's a little trickier to test the freezing point of water. Here is how to do it:
- Fill a tall container 3/4 full of water.
- Put the tall container with water in a wider container, like a mixing bowl.
- Put ice in the mixing bowl around the container of water.
- Cover the ice with salt.
- Stand the thermometer upright in the ice/salt mixture.
- Put the bowls in the freezer.
- Check the temperature every ten minutes.
Students should learn that the freezing point of water is 0 degree F or 32 degree C. Point this out on the Celsius to Fahrenheit Matchcard.
Let's Think About It
Which scale is easier to use?
- Celsius - which has a boiling point of 100 degrees for water and freezing point of 0 for water?
- Fahrenheit - which is what we are more used to when talking about weather temperatures?
There is no right or wrong answer. But the students should ponder the implications of the two different scales.
Take It Further
Explain that every substance has its own boiling point and freezing point. Those points are different for different substances. You may want to repeat the experiment and use other household liquids.
- Juice (which is water plus other liquid)
- salt water
- rubbing alchol
Also note that all substances have a freezing point and a melting point. For some substances, those temperatures might be too extreme for us to experiment on a kitchen stove or freezer.
A Tasty Twist
You will likely get no complaints if you take your freezer experiments a bit further and make homemade ice cream. The directions are also on the Celsius to Fahrenheit Marchcard.
- Add the following ingredients to a sandwich size resealable freezer bag:
- 1/4 cup of sugar
- 1/2 cup of milk
- 1/2 cup of whipping cream
- 1/2 teaspoon vanilla extract
- Seal the bag tightly.
- Add the following to a large freezer resealable bag and mix well:
- 2 cups of ice
- 1 cup of salt
- Put the small bag into the large bag. Seal tightly.
- Wrap a towel around the large bag to prevent frost bite. Rock the mixture back and forth.
You might want to save a little of the final mixture to experiment on the boiling point of ice cream. But don't be surprised if there is nothing left.
Print the Celsius to Fahrenheit Worksheet
This is MatchCard #5 of the Light and Energy Unit Study. Find more information on MatchCard Science below.
The Condensation MatchCard (Light and Energy-6) will take some of the temperature concepts from the Celsius to Fahrenheit Worksheet here even further.
Also, use the mathematical formulas to convert back and forth between the celsius and fahrenheit scales. Older students (7th grade and above) should know this formula. Younger students should be aware that it is available for use.
- 5/9(T - 32) Converts fahrenheit to celsius
- 9/5(T) + 32 Converts celsius to fahrenheit
The information pieces for the formula are on the third page of the Celsius to Fahrenheit MatchCard.