Unit 2 Concepts of Matter

1
Unit 2 Concepts of Matter

• C.4.A differentiate between physical and chemical
  changes and properties

2
Matter

• Matter is defined as anything that has mass and
  takes up space
• chemists use characteristic properties to tell
  substances apart and to separate them
• a substance is matter that has a uniform and
  definite composition

3
Physical Property

• Any quality or condition of a substance that can
  be observed or measured without changing the
  substances identity.
• Physical properties can be classified as
  Intensive and Extensive properties.

4
Identify Intensive and Extensive Properties

• Intensive Property is a physical property of the
  system that does not depend on the system size or
  the amount of material in the system.
• Examples of intensive properties include
  viscosity density freezing point melting
  point boiling point flammability

• Extensive Property an extensive property of a
  system does depend on the system size or the
  amount of material in the system.
• Examples of extensive properties include
  mass volume entropy energy electrical
  resistance

5
Chemical Properties

• Chemical Property is how a substance reacts in
  the presence of
• Air
• Acids
• Water
• Bases
• Chemicals
• Heat

6
Physical Changes in Matter

• Ex. grinding, cutting, melting, boiling

• change in a substance that doesnt change the
  identity of the substance
• Includes all changes of state (physical changes
  of a substance from one state to another)

7
Chemical Changes in Matter

• Chemical Change is a change in which a substance
  is converted into a different substance
• doesnt change the amount of matter present
• reactants substances that react
• products substances that form

8
Signs of Chemical Change

• Energy is always absorbed or given off
• Change in color or odor
• Production of a gas
• Irreversibility

9
States of Matter

• Solid
• Liquid
• Gas

10
Particle Movement In Matter

• Solids Liquids Gases

11
Solid

• definite volume
• definite shape
• atoms are packed together in fixed positions
• only vibrate in place
• Not easily compressible little free space
  between particles

12
Liquid

• definite volume
• indefinite shape
• atoms are close together
• not easily compressible little free space
  between particles

13
Gases

• indefinite volume and shape
• atoms move quickly
• atoms are far apart
• compressible lots of free space between
  particles
• vapor refers to the gaseous state of a substance
  that is a solid or liquid at room temperature.

14
Is It Chemical or Physical Change?

• Cookies are baked
• Water boils
• Salt dissolves in water
• Milk spoils
• A metal chair rusts
• Paper is torn
• A tree burns down