1. Physical and chemical changes

2. Physical Property: A characteristic of that can be measured without changing the chemical composition of a substance. Ex. Color, shape, size, density, melting point, boiling point, hardness, conductivity, malleability, ductility, state

3. Slide 8 of 10

4. Physical change: a change which does not change the identity of the substance Ex. Boiling, melting, changing shape, mixing, freezing, dissolving

5. Chemical change: A change where a new substance is formed from other substances, and has new properties Burning O2 and H2 gives off H2O and energy

6. Chemical property: A characteristic of a substance which indicates whether it can undergo a specific chemical change Ex. Flammability, reactivity, or non- reactivity

7. Signs of a Chemical Change color change, formation of a precipitate, gases given off, energy change- heating up or cooling down, light,

8. Signs of a reaction Precipitate: substance formed when a solid forms out of two liquids

9. Energy change Endothermic: chemical reaction that absorbs energy or heat Exothermic: chemical reaction gives off energy or heat

10. Exo vs. endo

11. Law of conservation of mass Law of Conservation of mass: mass of all substances before a chemical reaction is equal to the mass of all substances after the reaction

12. Extensive physical –Depend on the amount of the material present (ex. mass, length, & volume) Intensive physical –Does not depend on the amount of material present (ex. density, boiling point, ductility, malleability, color)

13. Boiling Point Boiling point- Temperature at which vapor pressure overcomes atmospheric pressure. Does Water always boil at 100ºC Why or why not? What would it do in space?