Bellringer What would happen to the particles of a substance if it were cooled to absolute zero? In other words, how would they behave? 2.Do you think anything can go from a solid state directly to gas?

Heating Objects Specific Heat: the amount of energy needed to raise the temp of one gram of any particular substance up 1 0 C This is a property of a substance. If something has a high specific heat, it takes a lot more energy to raise the temperature.

SPECIFIC HEAT Examples: water– HIGH specific heat (a lot of heat needed to increase its temperature). Metals – LOW specific heat (not much heat needed to raise its temperature). Low specific heat – heat goes in and out QUICKLY High specific heat – heat goes in and out SLOWLY

Thermal Energy Heat –The transfer of thermal energy –The particles use the energy to speed up OR to break down their bonds

Phase Change Energy content is responsible for the different phases of matter. Matter can be made to change phase when energy is added to or taken away from a substance.

States (Phases) of Matter Solids Liquids Gases Plasma –What is plasma? –Where is it found?

Thermal Energy What should happen to the temperature of ice as it melts? What should happen to the temperature of water as it boils?

Heating Curves

Melting and Boiling Points Melting and Boiling points are –Temperature at which melting or boiling happens –Specific to the material –Physical Properties Can be used to identify unknown substances

Heating Curves

Thermal Energy Endothermic Processes –Heat is being absorbed by the substance –Melting and vaporization

Melting- Solid to Liquid Melting is the changing of a solid to a liquid when the substance absorbs heat energy. Melting Point Water 0° C. Table salt 801° C. Diamond 3700° C.

Vaporization- Liquid to Gas Vaporization is the changing of a liquid to a gas when the substance absorbs heat energy. Vaporization occurring at the surface of a liquid is called evaporation.

Exothermic Processes –Heat is being taken away from the substance –Freezing and Condensation Thermal Energy

Condensation- Gas to Liquid Gases can change phase, also in a gas to liquid phase change. A substance in the gas phase that loses heat will change to a liquid. Gas changes to liquid is condensation.

Condensation Water vapor in surrounding air loses heat energy when it comes in contact with the cold glass. Water vapor condenses and becomes liquid drops of water.

Freezing- Liquid to Solid Opposite of melting: liquid changing to a solid is freezing. Freezing occurs when a substance loses heat energy. The freezing point of a substance is equal to the melting point!

Phase Change Graph

Sublimation – Solid to Gas Endothermic process of changing from a solid right into a gas. Solid to gas change occurs when the surface particles of a solid change directly into a gas without going through the liquid phase…

Sublimation – Solid to Gas You may notice this in the cold winter with snow. The snow does not melt, but slowly disappears.

Deposition – Gas to a Solid Exothermic process of changing from a gas right into a solid. FROST….