1. Why Does Matter Matter?

2. TEKS
4 (A) differentiate between physical and chemical changes and properties;
4 (B) identify extensive and intensive properties;
4 (D) classify matter as pure substances or mixtures through investigation of their properties.

3. Physical vs. Chemical Changes
Examples:
rusting iron
dissolving in water
burning a log
melting ice
grinding spices
Chemical
Physical

4. Sure Signs of a Chemical Change
Energy Change (Temperature and Light)
Gas Produced (not from boiling!)
Precipitate – a solid formed by mixing two liquids together
Color Change (Be Careful)

5. Physical Changes Some physical changes would be Phase Change
can be observed without changing the identity of the substance
Some physical changes would be
Phase Change
boiling of a liquid
melting of a solid
dissolving a solid in a liquid to give a homogeneous mixture — a SOLUTION.

6. Changes Quiz
Are the following changes considered chemical or physical?
1. Sharpening a pencil
2. Dissolving Koolaid in water
3. Silver Tarnishing
4. Alcohol evaporating
5. Milk souring

7. Chemical Properties and Chemical Change
Burning hydrogen (H2) in oxygen (O2) gives H2O.

8. Chemical Properties and Chemical Change
Burning hydrogen (H2) in oxygen (O2) gives H2O.
Chemical change or chemical reaction — transformation of one or more atoms or molecules into one or more different molecules.

9. Physical Properties ( see STAAR field guide)
What are some physical properties?
color
melting and boiling point
odor

10. Graphite — layer structure of carbon atoms reflects physical properties.

11. Physical vs. Chemical Properties
Examples:
melting point
flammable
density
magnetic
tarnishes in air

12. Physical Chemical Properties quiz
Combustible
Hard
13 Kilograms
Boils at 200°C
Density of 6.1g/cm³
Corrodes in air
Soluble in water
Volatile in water

13. What are Extensive and Intensive Properties?
All Physical Properties of Matter can be classified as Extensive or Intensive.
Extensive Properties- depend on the amount of matter
Ex) Mass
Intensive Properties- DOES NOT depend on the amount of matter.
Ex) luster, density (Mass/Volume ratio)
Determine Extensive or Intensive from the Physical properties on slide 9.

14. Intensive/Extensive Properties Quiz
Hard
13 Kilograms
Boils at 200°C
Density of 6.1g/cm³
Corrodes in air
Soluble in water

15. Mixtures and Pure Substances • Matter can be classified as a mixture or a pure substance.
What is the price difference in each type. Can you tell by looking or touching what kt it is?
Which are mixtures or pure?

16. Mixtures A mixture has variable composition
• A homogeneous mixture has the same properties throughout.
A heterogeneous mixture has different properties in different parts of the mixture.

17. Separation of Mixtures
distillation
filtration

18. Separation of Mixtures
Decantation- is a process of carefully pouring a solution from a container in order to leave the precipitate (sediments) in the bottom of the original container.
Chromatography- involves passing a mixture dissolved in a "mobile phase" through a stationary phase. Chromatography works on the principle that different compounds will have different solubilities and adsorption to the two phases, which will allow for their separation.

19. Water is a compound. All the components are the same—H2O molecules.
Pure Substances
A pure substance always has the same composition.
Pure substances are of two types:
Elements which cannot be broken down chemically into simpler substances
Compounds which can be chemically broken down into elements
Water is a compound. All the
components are the same—H2O molecules.

20. Matter Flowchart MATTER MIXTURE PURE SUBSTANCE yes no
Can it be physically separated?
Homogeneous Mixture
(solution)
Heterogeneous Mixture
Compound
MIXTURE
PURE SUBSTANCE
yes no
Can it be chemically decomposed?
Is the composition uniform?
Element
Bean mixture and sulfur (explain the difference between hetero and homo)
food coloring/water and water (separate the water by zapping it with electricity hince hydropowered futuristic cars)
sodium and sodium chloride
How can it be separated ?
Filtration
Distillation
Chromatography
Chemically
Electrolysis
Nuclear Reaction

21. Types of Mixtures Variable combination of 2 or more pure substances.
Heterogeneous – visibly separate phases
Homogeneous – Same throughout