10.3 The Phases of Matter pp. 240-244

10.3 The phases of matter On Earth, pure substances are usually found as solids, liquids, or gases. These are called phases of matter or states of matter.

10.3 The phases of matter A solid holds its shape and does not flow. The molecules in a solid vibrate in place, but on average, don’t move far from their places.

10.3 The phases of matter A liquid holds its volume, but does not hold its shape—it flows. Liquids flow because the molecules can move around.

10.3 The phases of matter A gas flows like a liquid, but can also expand or contract to fill a container. A gas does not hold its volume. The molecules in a gas have enough energy to completely break away from each other.

PLASMA The state of matter that does not have a definite shape or volume and whose particles have broken apart.

PLASMA (cont.) Natural plasmas are found in the Aurora Borealis. Artificial plasmas are found in fluorescent lighting.

Einstein-Bose Condensate The fifth phase of matter See www.brainPOP.com video

BOSE-EINSTEIN CONDENSATE Bose-Einstein Condensate forms when a gas composed of certain particles, referred to as "bosonic particles," is cooled to below a critical temperature. At this temperature, the matter wavelength becomes so large that the wave-like atoms overlap and start to oscillate in concert, forming the condensate. This condensate consists of a macroscopic number of particles, all of which are in a single quantum state, known as the "ground state of the system." Bose-Einstein condensate is a phase transition governed by the wave nature of the particles, as opposed to interactions between them.

KMT Generator

10.3 The phases of matter When they are close together, molecules are attracted through intermolecular forces.

10.3 The phases of matter The forces in chemical bonds are stronger than intermolecular forces.

10.3 Intermolecular forces Within all matter, there is a constant competition between temperature and intermolecular forces. When temperature wins the competition, molecules fly apart and you have a gas. When intermolecular forces win the competition, molecules clump tightly together and you have a solid.

10.3 Melting The melting point is the temperature at which a substance changes from a solid to a liquid. Melting is an endothermic change.

10.3 Boiling The temperature at which a liquid becomes a gas is called the boiling point. Boiling is an endothermic change.

Evaporation Evaporation is the change of a liquid into a vapor at a temperature below the boiling point. This occurs at any temperature between the melting point and the boiling point. However, the warmer the temperature the more quickly the water will evaporate.

Freezing Freezing is the phase change from a liquid to a solid. Freezing point: is the temperature at which this occurs Freezing is an exothermic change because energy is being taken out of the substance during this phase change It is the reverse process of melting , they occur at the same temperature 0ºC

10.3 Sublimation Sometimes a solid can change directly to a gas when heat energy is added. This process is called sublimation. Sublimation is an endothermic change.

Deposition Deposition is water vapor changing directly into a solid Ex. Frost on a window on a cold winter night

SUMMARIZING THE CHANGES OF PHASE Change of State Direction Endothermic or exothermic Example Melting Solid to liquid Endothermic ice melts into liquid water at 0°C Freezing Liquid to solid Exothermic Liquid water freezes into ice at 0°C Evaporation Liquid to gas Liquid water vaporizes into steam at 100°C Condensation Gas to liquid Steam condenses into liquid at 100°C Sublimation Solid to gas Dry ice sublimes into a gas