Topic: Chemistry Aim: Explain the different types of phase changes and the energy changes involved. Do Now: Write the aim on today’s notes sheet. Tape today’s notes sheet on the back of yesterday’s notes. HW: Properties Reading due Monday!

SOLID LIQUID GAS

Gas Liquid Gas Solid Liquid Solid Gas No definite shape or volume. Let’s summarize… Identify the phase being described (solid, liquid or gas): No definite shape or volume. Takes the shape of the container it is in and has a definite volume. Made up of high energy atoms. Atoms are tightly packed together. Molecules are cohesive. Has a definite shape and volume. Takes the shape of a closed container. Gas Liquid Gas Solid Liquid Solid Gas

Observe the phase change diagram Observe the phase change diagram. Identify the events that can occur to cause a phase change. HEAT IS RELEASED OR HEAT IS ABSORBED

Melting Substance absorbs heat energy

Substance GAINS energy

Melting S  L Solid ABSORBS heat energy Substance absorbs heat energy

Melting points of different substances Iron: 1536ºC Gold: 1063ºC Glucose: 150ºC Urea: 132-134ºC

Identify the phase change represented in the photographs below.

Substance loses heat energy LIQUID SOLID

Freezing L  S Liquid RELEASES heat energy Substance loses heat energy

Identify the process occurring in the animation.

Substance ABSORBSenergy LIQUID GAS

Vaporization GAS LIQUID L  G Liquid ABSORBS heat energy Evaporation: occurs on surface of liquid GAS Liquid absorbs heat energy LIQUID

Boiling points of different substances Alcohol (Ethanol): 79ºC Iodine: 184.3ºC Mercury: 356.9ºC Olive oil: 300ºC Jet fuel: 163ºC

Identify the phase change represented in the photograph.

Substance loses heat energy GAS LIQUID

Condensation GAS LIQUID G  L Gas RELEASES heat energy Gas loses heat energy LIQUID

Identify the phase change represented in the photograph.

Substance ABSORBSenergy SOLID GAS

Sublimation Solid  Gas Solid ABSORBS energy GAS Solid Solid absorbs heat energy Solid

Mt. Everest loses some snow cover due to common windstorms Mt. Everest loses some snow cover due to common windstorms. Snow is also constantly lost, invisibly, due to sublimation

Moth balls are used when storing clothing and other articles susceptible to damage from mold or moth larvae. Moth balls commonly undergo the process of sublimation. Sublimation is the process in which a solid changes directly to its gaseous phase, skipping the liquid phase.

Humid air to condenses into frost patterns, for example in single-layer window glasses and windshields.

Substance LOSES energy Deposition Substance LOSES energy SOLID GAS

Deposition G  S Gas RELEASES energy Solid GAS https://www.youtube.com/watch?v=Ft2KgtlP8Lk Solid Solid releases heat energy GAS

Let’s summarize… List the different types of phase changes. 2. Explain what happens to heat energy in each phase change.

5 1 2 4 3 A B C

When a liquid becomes a solid, energy does not change is released is absorbed is first absorbed, then released

_______ is the process in which liquid changes to gas below the boiling point.   Sublimation Condensation Evaporation Combustion

water that has passed through the glass On a hot day, the outside of a glass containing a cold drink becomes frosty. When touching the glass, it feels water that has passed through the glass water that has condensed from a gas in the air water that has solidified water that has absorbed energy

The change of a liquid to a solid is called freezing melting sublimation vaporization

When substances go directly from the solid phase to the gas phase, the phase change is called sublimation condensation evaporation vaporization

Mass number: 137 Atomic #: 56 # of neutrons: 137-56 81 neutrons

http://www.youtube.com/watch?v=XaDxwe8l3us&feature=related