1. Classification of Matter

2. Two Classifications of Matter
Pure Substance
Mixture

3. Pure Substance
A pure substance has the same composition throughout and does not vary from sample to sample.

4. Classification of Pure Substances
Elements
Compounds

5. Elements Elements are the basic building blocks of matter
They can not be decomposed by a chemical change
Each element has a unique set of chemical and physical properties
All elements are composed of atoms ( the basic unit of matter)
Elements are represented by symbols- the 1st letter is always capitalized and the last letter is lower case (ex. Na)

6. Examples: Properties of Cl: Properties of Na: Gas Solid Yellow
Sodium
Chlorine
Properties of Cl:
Gas
Yellow
Poisonous
Properties of Na:
Solid
Grey metal
Reacts violently with
water

7. Let’s explore more elements and their properties:

8. Compounds Compounds are composed of two or more elements.
Elements in a compound have had their physical and chemical properties altered as a result of being chemically bonded via a chemical reaction.
Compounds can be decomposed into two or more simpler compounds or elements by a chemical change.

9. Compounds are represented by:
Chemical Formulas which use element symbols and subscripts to show which elements and how many are in the compound.
Ex. NaCl, MgCl2

10. Examples: Properties of NaCl: Sodium Chloride Solid White
2Na + Cl2  2NaCl
Properties of NaCl:
Solid
White
Does not react with water.
Sodium Chloride
**Notice how the unique properties of the
elements in the compound have been changed.

11. Mixtures A mixture contains more than one substance.
The composition of a mixture can vary from sample to sample; however, each component of a mixture retains its own unique physical and chemical properties.
Mixtures can be separated by physical means.

12. Classification of Mixtures
Homogeneous
Heterogeneous

13. Homogeneous Mixtures Lemonade Vinegar
Homogeneous mixtures are also known as solutions.
They have a uniform composition and the components can not be seen as separate.
Lemonade
Vinegar

14. Heterogeneous Mixtures
Heterogeneous mixtures do not have a uniform composition and the components can be seen as separate.
Granite
Pizza

15. Separation Techniques
Filtration
Distillation
Crystallization
Chromatography

16. Filtrations Used to separate heterogeneous mixtures.
The mixture is poured through a piece of paper which allows the liquid part to pass and catches the solid portion.

17. Distillations Used to separate homogeneous mixtures.
This technique takes advantage of different boiling points.

18. Crystallization Used to separate homogeneous mixtures.
The liquid portion is allowed to evaporate and the solid portion remains behind as a crystal.

19. Chromotography
Separation occurs by allowing a mixture to flow along a stationary substance (usually chromotography paper).