Changes and Properties

Physical, Chemical, and Nuclear

Physical Change

• Form or appearance changes, but the properties of the substance are the same (same melting point, chemical composition, etc.)

Chemical Changes

• Identities of substances change during a reaction and new substances form

Nuclear Changes

• Nucleus of the atom changes to form new elements

Evidence of Chemical Change

• 1. Release of a Gas• 2. Formation of a Precipitate (powdery solid)• 3. Release or Absorption of Energy (heat or

light)• 4. Color Change

**Chemical Reactions

Properties

• Property – characteristic (way to describe) an object or substance

Physical Properties

• Those properties that we can determine without changing the identity of the substance we are studying

• Examples:• Hardness• Color• Melting Point• Density

Chemical Properties

• Describe the way a substance can change or react to form other substances

• Examples• Flammable• Reacts with

______

Station

What Happened Physical Chemical Nuclear

Why? (Evidence)

1 Rip paper

2 Fusion – 2 small nuclei combine to form 1 nucleus

3 Mix baking soda and vinegar - fizzes

4 Mix Pb(NO3)2 and NaOH – forms a white precipitate

5 Crumple paper

6 Burn copper – turns black on the end

7 Fission - 1 nucleus splits into several smaller nuclei

8 Dissolve salt in water

9 Melt ice