1. MATTER
AND
CHANGE

2. Chemistry:
The study of matter and the changes it undergoes.

3. Matter
Anything that has mass and takes up space

4. Alchemical view of matter

5. Matter
Atoms are the building blocks of matter

6. Matter
“Space-filling” models of molecules

7. Matter
Oxygen
Hydrogen
Each element is made of the same kind of atom

8. Each element is made of the same kind of atom with unique set of properties

9. Carbon
Uncut diamond
Graphite
Uncut diamond
with impurities

10. STATES OF MATTER: Solid, Liquid, Gas
(a) Particles in solid (b) Particles in liquid (c) Particles in gas

11. STATES OF MATTER SOLIDS Definite shape and volume
Particles of a solid packed tightly together
NOT easily compressed

12. SOLIDS

13. STATES OF MATTER LIQUIDS
Particles in close contact but arrangement is not orderly or fixed
Definite volume
NOT easily compressed

14. Liquid In a liquid H2O(l) Water molecules are in constant motion
there are appreciable
intermolecular forces
molecules are close
together
Liquids are almost
incompressible
Liquids do not fill the
container
some writing from Kotz (PowerPoints online)
H2O(l) Water
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31

15. STATES OF MATTER
GAS
Particles NOT in close contact and are constantly moving
No definite volume

16. Some Properties of Solids, Liquids, and Gases
Property Solid Liquid Gas
Shape Has definite shape Takes the shape of Takes the shape
the container of its container
Volume Has a definite volume Has a definite volume Fills the volume of
the container
Arrangement of Fixed, very close Random, close Random, far apart
Particles
Interactions between Very strong Strong Essentially none
particles

17. How to describe matter…
Extensive properties
Depends on the AMOUNT of matter in a sample
Mass
Volume
Intensive properties
Depends on the TYPE of matter in a sample
Color
Temperature
Density

18. SUBSTANCE Matter that has a uniform and definite composition
Every sample of a given substance has identical intensive properties because every sample has the same composition
Elements CANNOT be broken down into simpler components
Compounds CAN be broken down into elements

19. Examples of pure substances
GOLD
ALUMINUM

20. Compounds
Made of two or more different kinds of elements chemically combined in a fixed proportion.
for example:
Common table salt is a one to one combination of sodium atoms (Na) and chlorine atoms (Cl) = NaCl

21. What do we mean by “chemically combined”?
Elements in compounds are joined by chemical bonds.
Examples of chemical bonds:
Ionic bond (electrostatic attraction that binds oppositely charged ions)
Usually composed of metal and nonmetal atoms
Covalent bond (bond that forms by the sharing of electrons between atoms)
Usually composed of carbon atoms bonded to elements such as hydrogen, oxygen, nitrogen and sulfur

22. Properties of Compounds
Compounds can be broken down into simpler substances by chemical means but elements cannot.
Compounds and the elements from which they are formed have different properties

23. Examples of Compounds Sugar (sucrose)
Composed of carbon, hydrogen and oxygen
Sugar a sweet-tasting white solid but carbon is a black, tasteless solid; Hydrogen and oxygen are odorless gasses
Sugar Carbon Water

24. Sugar (sucrose)

25. Sugar (sucrose)

26. Properties of Matter Physical properties:
Can be observed without changing a substance into another substance
Boiling point, density, mass, volume, magnetic

27. Properties of Matter Physical changes Chemical changes
Changes in matter that do NOT change the composition of a substance
Changes of state (liquid to a gas), temperature (melting point), volume, crush, grind
Chemical changes
Changes that result in a new substance
Combustion, oxidation, decomposition

28. Mixtures Physical blend of two or more components
Heterogeneous = composition is variable throughout the sample
Homogeneous = composition is uniform throughout the sample

29. Classification of Matter