Physical and Chemical Changes

1
Physical and ChemicalChanges

• Objective 4
• TEKS 8A

Marivel Macias
2
Chemical Change

• The elements and/or compounds at the start of the
  reaction are rearranged into new product(s) (i.e.
  compounds or elements).

3
Oxidation of Iron - a chemical change

• For example iron has the potential to rust given
  the right conditions. This is a chemical
  property.
• If iron does rust, this is a slow chemical change
  since rust is an iron oxide with different
  properties than iron metal.

Iron oxygen water ? Iron rust.
4
Physical Change

• A physical change takes place without any changes
  in molecular composition.
• The same element or compound is present before,
  during and after the change.

5
Changes in States - a physical change

• The three states of matter are solid, liquid,
  and gas.

6
Digestion Physical or Chemical Change?

• Identify the following
• Biting an apple
• Chewing
• Swallowing
• Break down of carbohydrates in stomach, small
  intestine and large intestine.

7
Rock Cycle Physical or Chemical Changes?
8
Physical or Chemical Change?
9
Physical or Chemical Change?

• Phase Change
• From liquid water to gas vapor
• Boiling Point
• 100 degrees Celsius at 1 atm

10
Physical or Chemical Change?

• Dry Ice Sublimation
• carbon dioxide (s) ? carbon dioxide (g)

11
Physical or Chemical Change?
Plus Heat Energy
12
Physical or Chemical Change?
Iodine Zinc ? Zinc Iodide