1. Chapter 2
Matter

3. Chemistry The study of matter and how it changes
Matter – anything that has mass and takes up space
Mass – amount of matter any object has
Two types of matter-
Substance- Pure
Mixture- more than one substance

4. Two Kinds of Substances
Elements- Simplest kind of matter
Can’t be broken down further
All one kind of atom
116 kinds of elements
Each has a 1 or two letter symbol
Each behaves differently
Everything else is built of them

5. Matter Atoms are the building blocks of matter.
Each element is made of the same kind of atom.

6. Elements

7. Two Kinds of Substances
Compounds- Made of two elements chemically combined
Atoms stick together to make molecules
All molecules of a compound are the same
They mix in the same ratio
Compounds behave completely differently from the elements that make them
Pure Substances
Smallest part is a molecule

8. Matter Atoms are the building blocks of matter.
Each element is made of the same kind of atom.
A compound is made of two or more different kinds of elements.

10. Elements and Compounds
Element- All one atom

11. Elements and Compounds
Molecule- Different atoms stuck together

12. Elements and Compounds
Compound- All one molecule

13. Chemical Formulas Tell the type an number of atoms in a molecule
Symbols tell type
Subscripts tell number
Don’t write one as a subscript

14. Chemical Formulas
H2O
2 Hydrogen atoms
1 Oxygen atom

15. C12H22O11 Chemical Formulas 12 Carbon atoms 11 Oxygen atoms
22 Hydrogen atoms
11 Oxygen atoms

16. Molecules Most molecules form from different kinds of atoms
A few elements form molecules: Diatomics O2 N2 H2
Cl2 F2
Br2 I2
At2 I2 S8 P4

17. Pure Substance Elements and compounds
Only one kind of molecule or atom
Compounds have specific amounts of their elements
Compounds are completely different from their elements

18. Mixture Different substances mixed together Can be in any proportion
Keeps the same properties as the things that make it
Kool-aid
Mix something sweet, something wet and something red
Get something sweet, wet and red

19. Compound or Mixture Compound Mixture One kind of piece- Molecules
More than one kind -
Molecule or atoms
Making is a
chemical change
physical change
Only one kind
Variable composition

20. Two Types of Mixtures Heterogeneous- Homogeneous-
Different from place to place
Not evenly mixed
Chocolate chip cookie, gravel, soil
Homogeneous-
The same throughout
Evenly mixed
Kool-aid, sea water, air

21. Examples Heterogeneous Blood Chocolate Chip Cookie Soil Mixed Salad
Homogeneous
Air
Brass
Black Coffee
Motor Oil
Water

22. Liquid Mixtures Miscible- Immiscible-
Liquids that do dissolve in each other
Homogeneous
Gasoline
Immiscible-
Liquids that don’t dissolve in each other
Heterogeneous
Oil and water

23. Separating Mixtures
Filtration- process that separates mixtures based on the size of the particles
Distillation- process that separates the substances in a solution based on their boiling points.

24. Distillation:
Separates homogeneous mixture on the basis of differences in boiling point.

25. Distillation

26. Filtration:
Separates solid substances from liquids and solutions.

27. Chromatography:
Separates substances on the basis of differences in solubility in a solvent.

28. Solutions Homogeneous Mixture Mixed molecule by molecule
Example: Sugar in Water (same composition as any other portion)
Can occur between any state of matter

29. Common Solutions Gas in Gas- O2 in N (air) Liquid in Gas- Water Vapor
Gas in Liquid- CO2 in Water (soda water)
Liquid in Liquid- Acetic Acid in Water (vinegar)
Solid in Liquid- Kool Aid
Solid in Solid- Copper in Silver (sterling silver)

30. Suspensions Homogeneous Mixture Separate into layers over time
Large Particles
“Shake Well before using”
Shake sand and water; even spread out
Over time the sand will dissolve to the bottom.
Suspension

31. Colloids
Contains some particles that are intermediate in size between small particles in a solution and large particles in a suspension
Colloids don’t separate into layers
Example:
Milk is composed of water, sugar, proteins and fats
Fresh milk has a layer of cream on the top (mostly fat)
Milk is processed so fat is dispersed.
Homogenized Milk, which is a colloid

33. Common Colloids and Solutions
Clouds
Smoke
Blood
Shaving Cream
Jello
Mayonnaise
Milk
Solutions
Air
Sugar Water
Metallic Alloys
Salt Water
Steel
Carbonated Water
Tea

34. Properties A property is a something that describes matter
An adjective
Used to identify the matter
Used to distinguish between different types

35. Properties Words that describe matter (adjectives)
Physical Properties- a quality or condition of a substance that can be observed or measured without changing the substance’s composition
Chemical Properties- a property that can be observed by changing the type of substance

36. Properties Allow us to identify substances
Allow us to separate substances
Determine uses

37. Physical Properties
Can be observed or measured without changing the composition
Melting point , boiling point, hardness, odor, ability to conduct electricity and heat
Density – how heavy something is for its size
Ratio of mass to volume
If the density of substance is less than its surroundings, it floats

38. Examples of Physical Properties
1) Color
2) Solubility
3) Odor
4) Hardness
5) Density
6) Melting Point
7) Boiling Point
8) Size
9) Shape

39. Volume calculated by multiplying L x W x H
Liter the volume of a cube 1 dm (10 cm) on a side
1L = 1 dm3
so 1 L = 10 cm x 10 cm x 10 cm
1 L = 1000 cm3
1/1000 L = 1 cm3
1 mL = 1 cm3

40. Volume 1 L about 1/4 of a gallon - a quart
1 mL is about 20 drops of water or 1 sugar cube

41. Mass Weight is a force. Mass is the amount of matter.
1 gram is defined as the mass of 1 cm3 of water at 4 ºC.
1000 g = 1000 cm3 of water
1 kg = 1 L of water

42. Mass
1 kg = 2.5 lbs
1 g = 1 paper clip
1 mg = 10 grains of salt

43. Physical Properties
Can be observed or measured without changing the composition
Melting point , boiling point, hardness, odor, ability to conduct electricity and heat
Density – how heavy something is for its size
Ratio of mass to volume
If the density of substance is less than its surroundings, it floats

44. Which is heavier?
it depends

45. Density How heavy something is for its size.
The ratio of mass to volume for a substance.
D = M / V
Independent of how much of it you have
gold - high density
air low density.

46. Density Found by dividing the mass by volume D = m V
Units of g/mL or g/cm3
Water has a density of 1 g/mL

47. Density D M V
Cover up the one you are looking for to find the formula for the missing piece

48. Density M V D
A piece of wood has a mass of 12 g and a volume of 16 cm3 What is its density?
Steel has a density of 7.8 g/cm3. How much would 56 cm3 of steel weigh?
What would the volume of the same mass of water be?

49. Calculating The formula tells you how. Units will be g/mL or g/cm3
A piece of wood has a mass of 11.2 g and a volume of 23 mL what is the density?
A piece of wood has a density of 0.93 g/mL and a volume of 23 mL what is the mass?

50. Floating Lower density floats on higher density.
Ice is less dense than water.
Most wood is less dense than water.
Helium is less dense than air.
A ship is less dense than water.

51. Density of water 1 g of water is 1 mL of water.
density of water is 1 g/mL
at 4ºC
otherwise it is less

52. Measuring Temperature
0ºC
Celsius scale.
water freezes at 0ºC
water boils at 100ºC
body temperature 37ºC
room temperature ºC

53. Measuring Temperature
273 K
Kelvin starts at absolute zero (-273 º C)
degrees are the same size
C = K -273
K = C + 273
Kelvin is always bigger.
Kelvin can never be negative.

54. Temperature is different
from heat.
Temperature is which way heat will flow. (from hot to cold)
Heat is energy, ability to do work.
A drop of boiling water hurts,
kilogram of boiling water kills.

55. Units of heat are calories or Joules
1 calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1ºC.
A food Calorie is really a kilocalorie.
How much energy is absorbed to heat 15 grams of water by 25ºC.
1 calorie = 4.18 J

56. Chemical Properties Used to describe how substance reacts
How it changes
By combining with other substances
Or breaking apart
Reactivity how a substance combines with other substances
Things like flammability, rusting, etc.

57. Figure: 01-11
Title:
The chemical reaction between a copper penny and nitric acid.
Caption:
The dissolved copper produces the blue-green solution; the reddish brown gas produced is nitrogen dioxide.

58. Changes Two types- Physical Changes- no new type of matter is made
All the molecules stay the same
Chemical Change- a new type of matter is made
Atoms rearrange to make new elements or compounds

59. Physical Changes Might look a little different
Keeps original properties
Changing phases
Making a mixture
Cutting
Grinding
Dissolving

60. Physical Changes
Physical Change- alters a substance without changing its composition
Key Terms:
Boil
Freeze
Dissolve
Melt
Condense
Break
Split
Crack
Crush
Cutting

61. Chemical Changes One or more substances changing into a new substance
Completely new properties
Products are not at all like the reactants
Makes new odor, color, etc.

62. How do you know? 6 Ways to Tell Color Change
Energy absorbed or released (temp change)
Gas or Solid Produced
Odor
Precipitate (ppt)- solid that separates from solution
Not easily reversed

63. Chemical Reactions
In the course of a chemical reaction, the reacting substances are converted to new substances.

64. Compounds
Compounds can be broken down into more elemental particles.

65. What is it? Element, Compound or Mixture Silver Orange Juice Ice Tea
Potassium Chloride
Oxygen
Air
Pine Tree

66. Which is it?
Compound
Mixture
Element