1. Kinetic Theory

2. To understand the kinetic theory, we must first understand that temperature is really a measure of how fast the particles in a substance are moving

3. States of Matter Describe the spacing and movement of the particles in each picture that follows: Thornburg 2014

4. Kinetic energy = the energy of motion Objects with greater kinetic energy have a higher temperature Based on what you just watched, which state of matter has the highest relative kinetic energy? Gasses Kinetic Energy Thornburg 2014

5.  The Kelvin scale reflects the relationship between temperature and kinetic energy  For example, a container of hydrogen gas at 25 Kelvin would have half as much kinetic energy as a sample of hydrogen gas at 50 Kelvin  Absolute zero (0 Kelvin) is the temperature at which particles in a sample of matter are completely motionless Kelvin Scale Thornburg 2014

6. Solids Particles are very close together and moving very slowly Liquids Particles are fairly close together and moving fast Gasses Particles are far apart and moving very fast freezing condensation evaporation melting sublimation Thornburg 2014

7.  A gas is composed of extremely small particles (atoms or molecules)  The particles are constantly moving. The particles move in straight paths  The particles move independently of each other  The collisions are perfectly elastic (all of the energy of one particle is transferred to another particle during a collision) Kinetic Theory of Gasses Thornburg 2014

9.  A barometer is a tool used to measure the earth’s atmospheric pressure  Think of the earth’s atmosphere like a blanket of air pushing down upon us. Atmospheric Pressure Thornburg 2014

10.  The pressure exerted on an object by a gas  the gas particles are constantly colliding with the sides of a container, each collision exerts a force (pushes out) on the side of the container  Added together, these many small forces create a very large collective force Gas Pressure Thornburg 2014

11. http://www.chem.ufl.edu/~itl/2045/MH_sims/gas_sim.htm l Thornburg 2014

12.  The standard unit of pressure is based on the pressure of the earth’s atmosphere 1 atmosphere (atm)  We can use 3 different units to measure pressure: atmospheres(atm) kilopascals(kPa) mm of Mercury (mm Hg) 1 atm = 101.3 kPa = 760 mm Hg Units of Pressure Thornburg 2014

13. Use these terms… Increase / decrease More / less Thornburg 2014

14. Ponder This… Now that you have a basic understanding of kinetic theory, write an explanation (7 – 10 sentences) that answers the following: From last week’s experiments… Why did the balloon expand when it was placed on the hot plate? How did temperature have an effect on the rate at which food coloring diffused in water? Use the following terms in your paragraph: Pressuretemperaturekinetic energy Volumecollision(s)force Motionparticles Thornburg 2014

15. Solids Particles are ______ ________ _______ and moving _____ _____ Liquids Particles are _____ _____ _______ and moving _______ Gasses Particles are _____ ______ ________________ and moving _______ _________ freezing condensation evaporation melting sublimation