1 WHAT ARE THE PROPERTIES OF MATTER? PHYSICAL CHANGE? CHEMICAL CHANCE?

2 CHEMICAL REACTIONS

3 Physical and Chemical Properties All substances have properties that we can use to identify them.  idenify a person by his face, voice, height, finger prints, DNA etc..  matter has properties - and there are many of them.

4 Physical propertiesChemical properties Properties of Matter

5 Physical properties do not change the chemical nature of matter. IMF are changed in their observation. Examples of physical properties are: appearance, texture, color, smell, freezing point, boiling point, melting point, infra-red spectrum, opacity, viscosity and density.

6 Chemical properties do change the chemical nature of matter. INTRA- MOLECULAR forces change in their observation. Examples of chemical properties are: heat of combustion, reactivity, PH, flammability, being poisonous.

7 PHYSICAL & CHEMICAL CHANGES The changes that take place in substances may be categorized in two classes: Physical Change - does not produce a new substance (e.g., phase changes -melting, freezing, condensing-, breaking, crushing, cutting, and bending.) –IMF CHANGE!!! Chemical Change - produces a new substance (e.g., burning, rusting, photosynthesis, digestion, respiration, electrolysis, precipitation, and decomposition.) INTRA-MOLECULAR FORCES CHANGE!!!

8 Physical changes  melt a block of ice, you still have H 2 O at the end of the change.  break a bottle, you still have glass. Physical changes are about energy and states of matter.

9 Chemical changes  burn a log in a fireplace  light your Bunsen burner in lab  digestion of food, souring milk Chemical changes happen on a molecular level.

10  A chemical change occurs when a new substance is formed.  In a chemical reaction, bonds are broken and new bonds are formed between different atoms.  During this reaction, there is a rearrangement of atoms that makes or breaks chemical bonds.  What are chemical bonds?

(bubbles seen) 4. Explosion

12 References matter-and-energy/properties.html