 Solid  Liquid  Gas  Plasma

 Solid  Liquid  Gas  Plasma

 How are temperature and kinetic energy related?

In other words…  All matter is made of tiny particles (atoms) in constant motion  How MUCH they move depends on how much energy they have  Increased temperature will… increase kinetic energy= more movement So higher KE= higher temp

 Almost all matter expands as it gets hotter and contracts when it cools.  Temperature is a measure of the average kinetic energy of the particles in the object  Theoretically, absolute 0, (0 degrees Kelvin) has no movement of particles Never achieved in a lab

 Definite Shape and Volume  Solids are USUALLY the most dense There is one IMPORTANT exception- WATER! How do you know?

 Usually less dense than solids  Because they have more KE than solids and the particles can spread out more  Definite Volume  Can’t normally be squeezed into a smaller space  Indefinite Shape  Flow and take shape of container

 Least dense state of matter  Because they have the most KE than and the particles can spread out even more  No definite shape or volume  Molecules can be squeezed together or spread out to fill the space available

 Energy is RELEASED from the substance out to its surroundings  Ex’s- each of these products have molecules with LESS energy than they did before the phase change Freezing (liquid water has more energy than ice) Condensation (gas to liquid) Deposition (gas to solid)

 Energy is ABSORBED by the substance from its surroundings  Ex’s- each of these products have molecules with MORE energy than they did before the phase change Melting (ice has less energy than water) Evaporation (liquid  gas) Sublimation (solid  gas))

 Attractive Forces  Kinetic Energy Forces

 The force between two molecules  Holds them together weakly  Not as strong as “real bonds” (ionic, covalent)  Stronger in a solid than liquid, etc.

 The more particles move, the more they will spread out

 The state a substance depends on which force is greater  The kinetic energy of the particles OR  The strength of the attractions between the particles (attraction force)

Energy required to change a solid at its melting point to a liquid is equal to the energy released from the particles when a liquid is changed to a solid!

 A substance changes state when enough KE has been added to break the attractive forces and allow the molecules to spread out.

 Explain what is happening between the forces when a state changes on a cooling curve.  (ex- liquid to solid)

 The heat added to the system at the melting and boiling points goes into breaking the attractive forces. (not to speeding up the particles (KE))  Therefore the temperature of the substance does not rise during the phase change.

 heating curve of water animation heating curve of water animation

 The total energy absorbed in the heating curve is equal to the total energy released in the cooling curve of water  Melting/freezing pt: occur at same temperature  Boiling/condensation pt: occur at same temperature

 They are EQUAL!

 Explain what happens when a cold glass of water “sweats”

Condensation - gas to liquid Water particles in the air have more kinetic energy (heat) than the glass of water. As water particles get close to the glass, energy is transferred from the particles to the glass. This starts the following process… a. Particles lose kinetic energy, slow down, and come closer together. b.IF’s become strong enough to make particles merely rotate around each other. c.The energy they lose to turn into a liquid is the heat of vaporization. d. Substance is releasing energy to the surroundings (exothermic)

 Explain what happens when liquid water changes to ice.

Freezing - liquid to solid-. a. Particles lose kinetic energy & slow down. b. Substance releases energy to surrounding (exothermic) c. Attractive forces b/w particles become stronger than the particles’ motion, so the particles begin merely vibrating in place to form a solid. d. The amount of heat the particles must lose to turn into a solid is called the heat of fusion.

 Name the process described and then determine if it is exothermic or endothermic

1. Sublimation, Exothermic 2. Condensation, Exothermic 3. Evaporation, Endothermic 4. Sublimation, Endothermic 5. Condensation, Endothermic

1. Sublimation, Exothermic 2. Condensation, Exothermic 3. Evaporation, Endothermic 4. Sublimation, Endothermic 5. Condensation, Endothermic

1. Sublimation, Exothermic 2. Condensation, Exothermic 3. Evaporation, Endothermic 4. Sublimation, Endothermic 5. Condensation, Endothermic

1. Heating 2. Cooling 3. Both of the above 4. None of the above

10 1. IF are breaking 2. IF are being created (forming) 3. The phase change is increasing the temp 4. None of the above

1. Exothermic and a chemical change 2. Endothermic and a physical change 3. endothermic and a chemical change 4. Exothermic and a physical change

10 1. Solid to liquid 2. Solid to gas 3. Liquid to gas 4. Gas to liquid

10 1. Gas 2. Liquid 3. Solid 4. plasma

1. Gas 2. Liquid 3. Solid 4. plasma 0 of

 Why are there 2 portions of the phase change curve in which the temperature is not increasing? (the water is not removed from the heat source during any portion of time)

10 0 of Ice stage 2. Water + ice stage 3. Water stage 4. Water vapor stage

10 0 of Thermal energy 2. Kinetic theory 3. Law of conservation of mass 4. Law of conservation of motion

 Surface Tension!  Density of ice is special!  Contains H bonds (which are not actually bonds, but strong Intermolecular forces)  Gives water special properties like…