# Temperature / Pressure Fact Sheet

Temperature is a measure of the heat content. Larger temperature means more heat (hotter). Smaller temperature means less heat (colder).

Fahrenheit (F), Celsius (C) and Kelvin (K) are the most common temperature scales. Room temperature is 68 F, 20 C, or 293 K. Water freezes at 32 F, 0 C, or 273 K. Water boils at sea level at 212 F, 100 C, or 373 K.

Pressure (P), Volume (V), and Temperature (T) are related for gases by the Ideal Gas Law. As temperature increases, the pressure and/or volume of the gas will increase. As temperature decreases, the pressure and/or volume of the gas will decrease. Most solids and liquids also expand as their temperature increases.

The pressure of the Earth's atmosphere is "1 atmosphere" at sea level and decreases rapidly as one goes to higher altitudes. In Denver, Colorado at an altitude of 1.6 km (1 mile altitude), the pressure is 0.9 atmosphere. At 10 km (6 miles), the altitude at which planes can fly, the pressure is only 0.3 km; thus, planes are pressurized for passenger survival. In outer space, the pressure is near zero because there is very little gas in outer space. This lack of gas is a called a vacuum.

# Temperature / Pressure Experiment

Introduction: Students measure the temperature of ice water and warm water and monitor the temperature of warm water after ice is added. In addition, students insert a balloon filled with air into the ice water and warm water to see the effect of temperature on the balloon shape.

Supplies: The Boulder Valley School District FOSS Temperature kit includes the large beakers and thermometers needed for this experiment. A supply of ice and small balloons are also needed for this experiment.

Procedure: For each group of students, there is a beaker of ice water and luke warm water. The students measure the temperature of the ice water and warm water and record their results. With the balloon moderately filled with air, the balloon circumference (distance around the balloon) is measured. Then the balloon is inserted into the ice water, and the balloon circumference is measured once it has shrunk. The balloon is then inserted into the warm water beaker, and again the balloon circumference is measured. Finally, ice is added to the warm water and the temperature is monitored while the water cools off.

Ice Water Temperature : ____________________

Warm Water Temperature : ____________________

Balloon Circumference (distance around the balloon)

At room temperture : ______________________

In ice water : ______________________

In warm water : ______________________

Temperature Changes When Ice and Warm Water are Combined

0 min : __________________

1 min : __________________

2 min : __________________

3 min : __________________

4 min : __________________

5 min : __________________

10 min : __________________