Name:_____________________               Worksheet # 2 Quarter 1 Packet 4 Physical Properties             A property of matter that can be observed or measured without changing the composition of the substance. They are often used to identify substances.  Condensation             Condensation is a process directly opposite of evaporation. Condensation is the process which occurs when a gas changes to a liquid. It takes place when the temperature of a gas is lowerd below its boiling point. Every known gas can be condensed into liquid form. The molecules of gas can move very fast and are very far apart. When the molecules cool, they move slower and come closer together. If the gas is cooled enough, some of the molecules come so close together that they form a liquid, or condense.         Evaporation           Evaporation is the process which changes a substance from the liquid state into a vapor gas. Some of the more energetic molecules near the surface of a liquid may have and upward speed great enough to break through the surface film and fly into the space above as vapor molecules. This process is called evaporation. Liquids evaporate at all temperatures, but different liquids have different rates of evaporation. Heat speeds up the evaporation process. A liquid with a larger surface area evaporates faster than the same liquid with a small surface area. Circulation of air decreases the time of evaporation. When a liquid evaporates from the surface of something, that surface becomes cooler.   Matching: ___1.  state                    a. the quality of a surface which reflects light ___2.  density                b. the degree to which a liquid flows ___3.  transparency        c. the ability of matter to dissolve ___4.  solubility             d. form that matter can have ___5.  conductivity        e. ability of matter to conduct heat ___6.  reflectiveness      f. surface feel ranging from smooth to rough ___7.  texture                g. temperature at which a heated liquid boils ___8.  viscosity             h. the ease  at whichsomething can be seen through ___9.  boiling point         i. the ratio of mass to volume ___10. freezing point      j. temperature a liquid changes to a solid ___11. resistance           k. opposition to the flow of electricity
	Freezing Point            Freezing is the process which turns a liquid into a solid when its temperature is lowered to a certain point. Each substance has its own freezing point. For example, the freezing point of water is always 32*F or 0*C. Mercury freezes at -38*F, and alcohol must reach a temperature of -179*F before it becomes a solid. The freezing point of a material is the same as its melting point. The process of freezing is the reverse of melting. As a liquid cools, the motion of the molecules decreases; more molecules unite in an orderly fashion until the liquid becomes a solid.   Boiling Point            Boiling point is the temperature at which a liquid bubbles and turns into a vapor. The boiling point of a liquid depends on the atmospheric pressure. At sea level, water boils at 212*F or 100*C. At higher altitudes water boils at lower temperatures. Not all liquids boil at the same temperature, but the boiling point of a liquid always remains the same under the same atmospheric pressure. If a liquid is heated in an open container, an increase in heat will not change the temperature of the liquid once it has reached its boiling point.   Matching: ___1.  boiling point         a. the force or push on an area ___2.  melting point        b. the freezing point of water ___3.  freezing point       c. the temperature at which a liquid bubbles ___4.  0*C                     d. height ___5.  vapor                   e. temperature a liquid changes to a solid ___6.  atmosphere           f. the freezing point of mercury ___7.  -38*F                   g. temperature a solid changes to a liquid ___8.  altitude                  h. air that surrounds the earth ___9.  pressure                i. another name for gas ___10. -179*F                  j. freezing point of alcohol ___11. 100*C                   k. boiling point of water True or False: ___1. The freezing point of water is 32*F or 0*C. ___2. The freezing point of mercury is lower than that of alcohol. ___3. The process of freezing is the reverse of melting. ___4. Atmospheric pressure does not affect the boiling point. ___5. Water boils at a higher temperature at a higher altitude. ___6. At sea level water boils at 100*C. ___7. When steam rises from a liquid, a liquid is changing into a solid.. ___8. As a liquid cools, the motion of molecules increases. ___9. The boiling point can be changed by changing the pressure.