Physical and Chemical Changes

1
Physical and Chemical Changes
2
Physical ChangesPhysical changes- A change that
affects one or more physical properties of a
substance but does not change the chemical
identity of the substance.If you melt a block
of ice, you still have H2O at the end of the
change. 
3
Physical Changes
Any change in size, shape, form, or state where
the identity of the matter stays the
same Example cutting a watermelon into
slices tearing up a sheet of paper sharpening a
pencil Often easy to reverse with filtration,
magnetism, evaporation, distillation and
centrifuge (spinning)
4
Physical Change

• Signs that a physical change is taking place
• Change in Appearance
• Change in state of matter
• Observed without doing anything
• Measured quantity

Key words to look for Melts Evaporates Bent Conduc
tor
5
Physical ChangesSome common examples of
physical changes are melting, freezing,
condensing, breaking, crushing, cutting, and
bending.
6
Chemical ChangesChemical changes, or chemical
reactions, are changes that result in the
production of another substance. 
7
Chemical Changes

• Signs that a chemical change (reaction) is taking
  place
• Bubbles form
• Odor released/ forms
• Fizzing occurs
• Something burns
• A gas is released
• Heat produced
• Light produced
• Precipitate (solid) forms
• Rusting occurs
• A color change occurs

Key words to look for Burning Reacts Bubbles Tarni
shes Explodes Heats up Sours
8
Physical or Chemical Change?

• Painting Wood
• PHYSICAL

9
Physical or Chemical Change?

• Burning Paper
• CHEMICAL

10
Physical or Chemical Change?

• Digestion of food
• CHEMICAL

11
Physical or Chemical Change?

• Sugar dissolving in water
• PHYSICAL

12
Physical or Chemical Change?

• Iron turning red when heated
• PHYSICAL

13
Physical or Chemical Change?

• Evaporation
• PHYSICAL

14
Physical or Chemical Change?

• A pond freezing in winter
• PHYSICAL

15
Physical or Chemical Change?

• Melting ice
• PHYSICAL

16
Physical or Chemical Change?

• Cutting wire
• PHYSICAL

17
Physical or Chemical Change?

• Painting fingernails
• PHYSICAL

18
Physical or Chemical Change?

• Cutting fabric
• PHYSICAL

19
Physical or Chemical Change?

• Baking muffins
• CHEMICAL

20
Physical or Chemical Change?

• Shattering glass
• PHYSICAL

21
Physical or Chemical Change?

• Decomposition of old leaves
• CHEMICAL

22
Physical or Chemical Change?

• Wrinkling a shirt
• PHYSICAL

23
Physical or Chemical Change?

• An old nail rusting
• CHEMICAL