1. Mr. Sapalicio 8th grade Physical Science
Behavior of Gases 3.3

2. Measuring Gases
Volume- amount of space that matter takes up (vol. of gas is same as it’s container.)
Measured in cubic centimeters (cm3), Milliliters (Ml), and Liters (L).
Temperature- measure of average energy of motion of particles of matter.
Faster the particles move the greater the energy and the higher the temperature
thermometer is a speedometer for molecules.
20 degrees Celsius average gas particle travels 500 meters per second. Twice the speed of a jet plane.

3. Measuring Gases (cont.)
Pressure- the force of outward push divided by area of walls of container.
Pressure is measured in units called Pascals (Pa) or kilopascals (kPa). 1 kPa= 1000 Pa.
Firmness of gas filled object comes from pressure of gas.
When something filled with air is punctured the many gas particles inside are able to hit the hole rather than the gas particles outside so air is released rather than enter.
Pressure will drop until it is equal to the pressure outside.

4. Temperature and Volume Charles’s Law
When the temperature of a gas is increased at constant pressure, its volume increases.
When the temperature of a gas is decreased at constant pressure, it’s volume decreases.
Hot air balloon- they put hot air inside it becomes less dense and starts to float in the cooler more dense air. Fewer gas particles moving at a high rate, but fewer. So its less dense.
Car tires- The molecules don't expand or contract with temperature. At higher temperature they move faster, hit the walls more often, and bounce harder when they do.
When the air in the tires cools down, the pressure drops. That also makes the tire a little bit flat

5. Directly proportional
Directly proportional- two variables that pass through the origin.
“Directly proportional means that both variables increase or decrease at the same time.”

6. Pressure and Volume Boyle’s Law
When the pressure of a gas at constant temperature is increased, the volume of the gas decreases.
When the pressure is decreased, the volume increases.
Balloon to the bottom of a pool- Balloon will shrink, the pressure on the bottom of a pool is higher then at the top. Boyle’s law.
When you increase the pressure in a bike tire, there is no space left inside so the volume for more gas is smaller.
When you deflate the tire there is more volume because there is not a lot of pressure.

7. Inversely proportional
Inversely proportional- means that one variable goes up while the other goes down