2. States of matter 1.Solids Definite shape Definite volume Particles are pulled close together  Repeating patterns called crystal lattice (ex. Sugar & salt)  Non-repeating pattern called amorphous (ex. Plastics & rubber)  Particles exhibit a slight vibration

3. 2. Liquids No definite shape – will take shape of container Definite volume Particles are further apart than in a solid Particles may still be in clumps Surface Tension –Results from an inward pull of the molecules of the liquid bringing molecules on the surface closer together

4. Viscosity - a liquids resistance to flowing High viscosity: liquid flows slowly (cold syrup) Low viscosity: liquid flows fast (vinegar) HIGH LOW

5. GASES No definite shape – will take shape of container No definite volume Particles are spread out and move independently of each other

6. Melting – solid to a liquid [Solid particles vibrate faster when heat is added until they break away form each other] Melting point – temperature at which the solid changes into a liquid Ex. – melting point of ice = 32 o F or 0 o C or 273 K The temperature will remain at 0 o C until all ice is melted Changes of states--- When a substance goes from one state of matter to another

7. Vaporization – liquid to gas [two types] 1. Boiling-- occurs below surface as well as on the surface  As more heat (energy) is absorbed by the liquid the temperature rises until the particles begin to break apart and move independently of each other (gas)

8. Boiling point – temperature at which a liquid begins to boil  Water = 212 o F or 100 o C or 373 K  Temperature will remain the same until all the water has been converted to steam  Liquid water and steam (water vapor) can both be 100 o C but steam has more energy so can cause a more serious burn than the liquid state Boiling point and Air pressure Boiling point depends on the pressure of the air above it At sea level – BP is 100 o C In mountains - BP is 95 o C because air pressure is lower

9. Evaporation Occurs on surface only Ex. - Puddle on ground getting smaller

10. Summary of phase changes http://www.kentchemistry.com/ links/Matter/HeatingCurve.htm H 2 O(s) H 2 O(l) H 2 O(g) Solid liquid gas

11. Cooling of a gaseous substance –Condensation – going from a gas to a liquid Gas particles have a high amount of energy – when cooled –particle motion slows down – causes the attractive forces to draw the particles closer together causing them to clump together and form a liquid By removing more energy (cooling) from the liquid the particles align themselves in a row and a solid is formed. This process is called Freezing The temperature at which a liquid becomes a solid is its freezing point The freezing point and melting point of a substance are the same By removing more energy (cooling) from the liquid the particles align themselves in a row and a solid is formed. This process is called Freezing The temperature at which a liquid becomes a solid is its freezing point The freezing point and melting point of a substance are the same

12. Sublimation – substance goes directly from a solid to a gas Ex: dry ice – CO 2 (s) solid carbon dioxide Moth balls Solid air fresheners Snow and extreme cold Deposition – substance goes directly from a gas to a solid Ex: cold air (gas) turns to frost on windows

13. The Law of Conservation of Energy – Energy is neither created or destroyed but can be converted from one form to another