Effects of Heat on Matter powerpoint presentation

Effects of heat on matter

1. Phases of Matter

2. Kinetic Theory All matter is made of atoms and molecules that act like tiny particles.

3. Kinetic Theory These tiny particles are always in motion. The higher the temp., the faster the particles move.

4. Kinetic Theory At the same temp., more massive (heavier) particles move slower than less massive (lighter) particles.

5. SOLIDS Definite shape ? YES Definite volume ? YES Molecules in a solid are tightly packed and constantly vibrating.

6. LIQUIDS Definite shape ? NO Definite volume ? YES Some liquids flow more easily than others. The resistance of a liquid to flow is called viscosity . Honey has a high viscosity compared to water.

7. GASES Definite shape ? NO Definite volume ? NO The particles in a gas are spread very far apart, but can be compressed by pumping them into a restricted volume.

8. Phase Changes Changes in phase are examples of physical changes. Melting: solid  liquid Freezing: liquid  solid Vaporization: liquid  gas Condensation: gas  liquid Sublimation: solid  gas

9. Changes of State GAS SOLID Deposition Sublimation Vaporization Condensation Melting Freezing LIQUID Melting

10. ENERGY is the ability to change or move matter. Energy is ABSORBED when substances melt or evaporate. NOTE: our bodies cool down when our sweat evaporates. Energy is RELEASED when substances freeze or condense. ENERGY TRANSFERS!!!

11. Melting The change of state from solid to liquid . Energy (heat) is absorbed by the substance that is melting.

12. Freezing The change of state from liquid to solid . Opposite of melting. Energy (heat) is released by the substance undergoing freezing.

13. Evaporation Evaporation: the process in which molecules escape from the surface of a liquid. Change from state from a liquid to a gas .

14. Boiling Occurs throughout the liquid. boiling point/temperature is determined by pressure Energy (heat) is absorbed by the liquid.

15. Boiling

16. Boiling A rapid state of evaporation that takes place within the liquid as well as at it ’ s surface. Like evaporation, cooling of the liquid results. Boiling point: the temperature at which the vapor pressure of the liquid equals the ambient (surrounding) pressure. ***the normal boiling pt = the temp at which a liquid ’ s vapor pressure = 760 mm Hg or 1 atm

17. Vaporization (evaporation and boiling) vapor pressure: the pressure exerted by the vapor of the liquid on its surface at equilibrium in a closed container; increases as temperature increases ***liquids with high boiling points have low vapor pressures and relatively strong intermolecular attractions.

18. Condensation The change of state from gas to liquid. The opposite of evaporation. Energy (heat) is released by the liquid (Warming of the liquid results)

19. Condensation

20. Sublimation The change of state from solid to gas.