kinetic theorykinetic theory

matter is made of atoms & moleculesmatter is made of atoms & molecules– they act like tiny particles that are ALWAYS in they act like tiny particles that are ALWAYS in

motionmotion

– the higher the temperature of the substance the higher the temperature of the substance is, the faster the particles moveis, the faster the particles move

– at the same temperature, more massive at the same temperature, more massive particles move slower than less massive onesparticles move slower than less massive ones

helps to explain the differences helps to explain the differences between the three common states of between the three common states of matter: solid, liquid, and gasmatter: solid, liquid, and gas

states of matterstates of matter solids have a definite shape and volumesolids have a definite shape and volume

– examples: ice, marble, dry iceexamples: ice, marble, dry ice

liquids change shape, not volumeliquids change shape, not volume– examples: water, mercuryexamples: water, mercury

gases change both shape and volumegases change both shape and volume– examples: carbon dioxide, helium, nitrogenexamples: carbon dioxide, helium, nitrogen

fluid: a nonsolid state of matter in which the fluid: a nonsolid state of matter in which the atoms or molecules are free to move past each atoms or molecules are free to move past each other, as in a gas or liquidother, as in a gas or liquid

plasma is the most common state of matterplasma is the most common state of matter– examples: fire, lightningexamples: fire, lightning

– plasma: a state of matter that consists of free-moving plasma: a state of matter that consists of free-moving ions and electronsions and electrons

three common statesthree common states

energy’s roleenergy’s role because they are in motion, all particles of matter because they are in motion, all particles of matter

have kinetic energyhave kinetic energy– energy: the capacity to do workenergy: the capacity to do work

temperature is a measure of average kinetic energytemperature is a measure of average kinetic energy– temperature: a measure of how hot (or cold) something is; temperature: a measure of how hot (or cold) something is;

specifically, a measure of the average kinetic energy of the specifically, a measure of the average kinetic energy of the particles in an objectparticles in an object

thermal energy depends on particle speed and thermal energy depends on particle speed and number of particlesnumber of particles– thermal energy: the total kinetic energy of a substance’s thermal energy: the total kinetic energy of a substance’s

atomsatoms

kinetic energy & states of kinetic energy & states of mattermatter

thinking questionsthinking questions

1. Compare the temperature and thermal energy of hot soup in a small mug and that of hot soup in a large bowl.

2. Which particles have the strongest attraction between them: the particles of a gas, the particles of a liquid, or the particles of a solid?

3. Use the kinetic theory to explain how a dog could find you by your scent.