Lesson #22

​BELLWORK: Watch the video and fill in the blank

Thermometers

Many thermometers measure
temperature with a liquid that expands
when it gets warmer and contracts
when it gets cooler.

The red liquid rises or falls in the glass
tube as the temperature changes.
Temperature is read off the scale at
the height of the liquid in the tube.

Temperature Scales

Although some scientists use the Celsius scale.

The SI scale for measuring temperature is the Kelvin scale. I

The U.S. uses the Fahrenheit scale.

Temperature scale conversion

To convert a temperature from Celsius to Kelvin, just add 273
to the Celsius temperature.

For example, 10 °C equals 283 Kelvin.

C to F

Converting between Celsius and Fahrenheit is more
complicated.

Celsius → Fahrenheit: (°C × 1.8) + 32 = °F

Fahrenheit → Celsius: (°F - 32) ÷ 1.8 = °C

Absolute Zero

The lowest temperature that is theoretically possible, at which
the motion of particles that constitutes heat would be
minimal.

It is zero on the Kelvin scale, equivalent to –273.15°C or
–459.67°F.