1. MATTER

2. Chemistry is the study of the composition and behavior of matter.
Introduction
Chemistry is the study of the composition and behavior of matter.

3. Matter is anything with mass and volume
book
air
smoke

4. LAW OF CONSERVATION OF MATTER
Matter cannot be created or destroyed, it can only be changed from one form to another.

5. Mass is a measure of the amount of material within an object.
***Mass is independent of gravity; weight is not!

6. LAW OF CONSERVATION OF MASS
Mass cannot be created or destroyed, it can only be changed from one form to another.

7. 10 g reactants → 10 grams products
20 mlc reactants → 20 mlc products
***The Law of Conservation of Mass tells us that what we start with must EQUAL what we end up with!

8. Volume is the amount of space occupied by an object

9. Physical States of Matter
Solid
definite shape and definite volume

10. Liquid
definite volume, takes shape of container (indefinite shape)

11. Gas
takes volume and shape of container

13. Plasma
Gas particles that have broken apart to become positive ions & stream of electrons

14. Physical vs Chemical Changes
1. In physical changes, the identity of a substance remains the same.
Example:
liquid water is heated to form water vapor
H2O (l) → H2O (g)

15. 2. In chemical changes, the identities of substances change and new substances form.
Example:
Mercury (II) oxide → mercury + oxygen
2HgO → 2Hg + O2

16. Evidence of Chemical Change
Formation of a gas (bubbles)
Evolution of heat and/or light
Formation of a precipitate

17. Solution A + Solution B → solid + solution C
Precipitate:
A solid produced in a chemical reaction between solutions
Solid “falls out” of solution
Solution A + Solution B → solid + solution C
[two homogeneous mixtures] [heterogeneous mixture]

18. A change in color is not a reliable indicator of a chemical change.

19. In chemical equations, the reactants are on the left side of the arrow, and the products are on the right side of the arrow.
Reactants → Products

20. Examples: 2Na + Cl2 → 2NaCl Reactants → Products 2H2 + O2 → 2H2O

21. Properties of Matter
Chemical properties can only be identified by trying to cause a chemical change.
Examples include reactivity with oxygen (rusting of iron), flammability

22. Physical properties can be determined without changing the nature of the substance.
Examples include color, state, texture, melting point, boiling point, density

23. Two types of physical properties:
Intensive Physical Properties-
depend only on the identity of the substance
Examples: density, boiling point, melting point

24. 2. Extensive Physical Properties
depend on the amount of substance present
Examples: volume, mass, length, width

25. Classification of Matter
All matter is classified as a PURE SUBSTANCE or a MIXTURE.

26. 1. Pure substances include elements and compounds.

27. A. Elements: All matter is composed of elements
Fundamental unit of matter
Composed of one kind of atom
Cannot be broken down by ordinary chemical means

28. -Currently more than 114 identified
Each has specific properties and characteristics
Each has a unique symbol

29. First is capitalized, second is not
Chemical Symbols:
One or two letters
First is capitalized, second is not
often first letter or first two letters of the name
Carbon C
Calcium Ca
Boron B
Bromine Br

30. Some symbols are derived from their Latin names:
Iron Fe (Ferrum)
Sodium Na (Natrium)
Silver Ag (Argentum)

31. B. Compounds
The chemical combination of two or more elements
Has a formula
Can be broken down by ordinary means into elements

32. H2O is a compound made up of the elements hydrogen and oxygen
NaCl is a compound made up of the elements sodium and chlorine

33. Examples of Pure Substances:
pure water (compound): H2O
not tap water
carbon (element):C
sodium chloride (compound):NaCl

34. Sodium chloride (table salt)
Each pure substance has unique properties allowing us to recognize and distinguish one from another.
Sodium
Chlorine
Sodium chloride (table salt)
soft, silvery metal
reacts violently with water
pale greenish yellow gas
poisonous
colorless crystals
relatively non-toxic
dissolves easily in water

35. 2. Mixtures:
Each part of a mixture retains its original properties
Most matter = mixtures

36. All mixtures can be separated into their original parts by using physical changes/properties.

37. Two types of mixtures:
1. Homogeneous-
Composition uniform throughout
Homogeneous mixtures are also called SOLUTIONS
All pure substances are homogeneous.

38. EXAMPLES:
salt water
sugar water
air

39. 2. Heterogeneous
Composition varies in properties and appearance throughout
Most mixtures are heterogeneous

40. EXAMPLES:
sand in water
salt and sugar
tap water
concrete

41. MATTER Pure Substances Mixtures
Homogeneous
Mixtures
Heterogeneous
Mixtures
Compounds
Elements

42. Energy is the ability to do work
ENERGY OF MATTER
Energy is the ability to do work

43. Every change in matter involves a change in energy.
Endothermic processes absorb energy
Exothermic processes release energy

44. Law of Conservation of Energy:
Energy cannot be created or destroyed, it can only be changed from one form to another.

45. Heat is the energy transferred between objects that are at different temperatures.
Temperature is a measure of the average kinetic energy of the particles in an object

46. Stop and do today’s homework