2Matter and Temperature States of matterDependent on temperatureSolidLiquidGasPlasma
3Solid Definite shape and definite volume The particles in a solid are held close together by forces between them. The particles are in constant motion but lack the energy to move out of position.Kinetic theory states that all particles are in constant motionCrystalline solidsThe particles are arrangedin repeating geometric patterns.Amorphous solidsSolids that have no form – not crystalsGlass, some plastics and wax
4Liquids Indefinite shape and definite volume Liquids posses enough kinetic energy to move over and around each other.This allows them to flowBut like solids they are held too close together though to be able to compress them.They take the shape of their container
5Gases Indefinite shape and indefinite volume Gases posses enough kinetic energy to separate completely from one anotherThey are free to move inall directions until they havefilled their container.P1V1 = P2V2Since they are not closetogether the particles of agas can be squeezed together
6Example: the sun and most stars Plasma-is formed by passing electric currents through gases. In a plasma with an electrical current running through it, negatively charged particles are rushing toward the positively charged area of the plasma, and positively charged particles are rushing toward the negatively charged area. In this mad rush, particles are constantly bumping into each other. These collisions excite the gas atoms in the plasma, causing them to release photons of energy.Example: the sun and most stars99% of the mass of our solar system is plasma<Solid> <Liquid> <Gas> <Plasma>
7Thermal ExpansionIn general, when a substance is heated up it takes up more space (expands) and when it cools down it takes up less space (contracts).It takes up more space because the increase in temperature causes and increase in the movement of particles. (ice is an exception)
8Changes in State Melting – solid -> liquid Freezing – liquid -> solidBoiling – liquid -> gasCondensation – gas -> liquidEvaporation – liquid changing toa gas at temperatures below theboiling point.Sublimation – solid -> gas withoutfirst melting
9Heat and state changesHeat of fusion – energy needed to change a substance from a solid to a liquid. (334kj/kg for water)Heat of vaporization – energy needed to change a substance from a liquid to a gas. (2260 kj/kg for water)In general as a substance is heated it’s temperature increases.This is true except at the exact point of melting and boiling. At this time the energy that is added by heat is used to break the bonds holding the particles together and not to raise the temperature.Why does sweating cool you off?
10Density Lab Density = mass/volume Density is describing how close the atoms are together and how heavy those atoms are.If I were to ask you to place 1 ton of feathers in the parking lot and then place 1 ton of lead in the parking lot, which would make a bigger pile?
11Homework Day 1: Read pp. 213-227. Day 2: Vocab. #2,3,7,8,9,10 Day 3: Check. Concepts: #1,2,3,Day 4: Answer questions to Review p. 227 #1,2,3. and Understanding Concepts #14Day 5: Finish Lab #11-Density, from class.No test this week. You will get the CH. 8 test next week.