1. Introduction to Matter

2. Review… What is matter? Elements, Compounds, Mixtures
Classification of Matter
Pure substance vs. mixture
Heterogeneous vs. homogeneous mixture

3. Properties of Matter Physical Property:
any property that is measurable whose value describes a physical system's state
EXAMPLES: color, melting point, boiling point, density
Chemical Property:
any of a material's properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity
EXAMPLES: flammability, reactions

4. Chemical or Physical Property?
flammability
color
density
boiling point
texture
freezing point
mass
reactivity with acids
Ability to rust
solubility
volume
rate of decomposition

5. Density Ratio of mass to volume
Formula: D=m/v
characteristic property – does not depend on sample size
varies with temperature
The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244 grams, what is the volume of the aluminum?

6. The Kinetic-Molecular Theory
A scientific theory that explains the behavior of matter (KMT)
atoms and molecules are constantly in motion , and we measure the energy of these movements as the temperature of that substance. This means if there is an increase in temperature, the atoms and molecules will gain more energy (kinetic energy) and move even faster. Assumptions of KMT:
Matter is composed of particles
Degree to which particles are spread out relates to state of matter
These particles are in constant, random motion
LIQUID
SOLID
GAS

7. Properties of Gases no definite shape or volume low density
compressibility
exert pressure
have mass, take up space
fluidity
diffusion & effusion

8. Diffusion
the tendency of molecules to move from an area of high concentration to an area of low concentration until the concentration is uniform throughout.
Think about the water & food coloring you’ve observed…

9. Liquids Properties of liquids:
More ordered than gases, but particles still move freely
Relatively high density
Relative incompressibility
Ability to diffuse
Surface tension

10. Solids Properties of solids: Types of solids:
Highly ordered, particles can only vibrate around fixed points
Definite shape/volume
High density/incompressibility
Types of solids:
Crystalline
Particles arranged in orderly pattern
Amorphous
Particles arranged randomly

11. Phase Changes
Phase: any part of a system that has uniform composition and properties
Possible Phase Changes:
S  L = melting
S  G = sublimation
L  S = freezing
L  G = evaporation (rm temp)
L -> G = vaporization (heat)
G  L = condensation
G  S = deposition
Which phase changes involve an INPUT of energy?
Which phase changes involve a RELEASE of energy?

12. Changes in Matter
Physical Change: change that does not involve a change in the identity of the substance
EXAMPLES: cutting, changes of state
Chemical Change: one or more substances
converted into different substances
EXAMPLE:
Carbon + Oxygen  Carbon Dioxide

13. Chemical or Physical change?
Sodium hydroxide dissolves in water
Iron rusts
A sodium pellet is sliced in two
Water is heated and changed to steam
Potassium chlorate decomposes to potassium chloride and oxygen gas
Hydrochloric acid reacts with KOH to produce heat
Sodium catches fire when placed in water
Evaporation of ethanol
Ice melting
Milk sours
Sugar dissolves in water
Writing on a paper with ink
Food is digested in the stomach
Water is absorbed by a paper towel
Tire inflated with air