1. Matter & The Atom

2. Matter
The term matter describes all of the physical substances around us: your table, your body, a pencil, water, and so forth

3. Matter Anything that has mass and takes up space (has volume)
Made up of different kinds of atoms

4. Matter
Includes all things that can be seen, tasted, smelled, or touched
Does not include heat, sound, or light

5. Matter is made of atoms

6. Models
Models are often used for things that are too small or too large to be observed or that are too difficult to be understood easily

7. Models
In the case of atoms, scientists use large models to explain something that is very small
Models of the atom were used to explain data or facts that were gathered experimentally.
So, these models are also theories

8. Early Models of the Atom Bohr
Electrons move in definite orbits around the nucleus

9. Early Models of the Atom Chadwick
Discovered the neutron

10. Modern Model of the Atom The electron cloud
Sometimes called the wave model
Spherical cloud of varying density
Varying density shows where an electron is more or less likely to be

11. Atomic Structure
Nucleus
Protons
Neutrons
Electrons

12. Atomic Structure Electrons Tiny, very light particles
Have a negative electrical charge (-)
Move around the outside of the nucleus

13. Atomic Structure Protons Much larger and heavier than electrons
Protons have a positive charge (+)
Located in the nucleus of the atom 

14. Atomic Structure Neutrons Large and heavy like protons
Neutrons have no electrical charge
Located in the nucleus of the atom 

15. Atomic Structure

16. Describing Atoms Atomic Number = number of protons
In a neutral atom, the # of protons = the # of electrons

17. Describing Atoms
Atomic Mass Number - equal to the number of protons plus neutrons.

18. Ions An atom that carries an electrical charge is called an ion
If the atom loses electrons, the atom becomes positively charged (because the number of positively charged protons will be more the number of electrons)

19. Ions An atom that carries an electrical charge is called an ion
If an atom gains electrons, the atom becomes negatively charged (more negative charges than positive charges)

20. Ions The number of protons does not change in an ion
The number of neutrons does not change in an ions
So, both the atomic number and the atomic mass remain the same.

21. Ions
This atom has lost an electron. Now it has one more proton than electron.
One more proton means one more positive charge.
This makes the total charge of the atom POSITIVE.
This atom has gained an electron. Now it has one less proton than electron.
One less proton means one less positive charge.
This makes the total charge of the atom NEGATIVE.

22. Mixtures, Elements and Compounds
A Matter of Fact
Mixtures, Elements and Compounds

23. Mixtures, elements, compounds
Scientists like to classify things.
One way that scientists classify matter is by its composition.
Ultimately, all matter can be classified as mixtures, elements and compounds.

24. Why isn’t it a good idea to classify matter by its phases?
Because one kind of substance can exist in more than one phase – such as H20. And matter changes phases rather easily.

25. Why isn’t matter classified according to its physical characteristics, such as color?
Scientists wouldn’t find it very useful to group gold, sunflowers, and the sun together.

26. Scientists ask themselves these questions?
Is the matter uniform throughout?
Can it be separated by physical means?
Can it be separated by chemical means?

27. By asking these questions scientists can classify matter into:
Mixtures – two or more substances that are not chemically combined with each other and can be separated by physical means. The substances in a mixture retain their individual properties.
Solutions – a special kind of mixture where one substance dissolves in another.
Elements – simplest form of pure substance. They cannot be broken into anything else by physical or chemical means.
Compounds – pure substances that are the unions of two or more elements. They can be broken into simpler substances by chemical means.

29. Is it uniform throughout?
If the answer is no, the matter is a heterogeneous mixture.
Considered the “least mixed.”
Does not appear to be the same throughout.
Particles are large enough to be seen and to be separated from the mixture.

30. Examples of heterogeneous mixtures
Sand and pebbles
Oil and water
Powdered iron and powdered sulfur

31. Granite is a heterogeneous mixture.

32. Is it uniform throughout?
If the answer is yes, the matter is homogeneous (looks the same throughout).
That leads us to another question.

33. Can it be separated by physical means?
If the answer is yes, the matter is a homogeneous mixture or solution.

34. Homogeneous Mixtures A mixture that appears to be the same throughout.
It is “well mixed.”
The particles that make up the mixture are very small and not easily recognizable.

35. Examples of homogeneous mixtures
Milk, toothpaste, and mayonnaise are homogeneous
mixtures. They are also colloids.

36. Colloids
In a colloid the particles are mixed together but not dissolved.
The particles are relatively large and are kept permanently suspended.

37. Colloids A colloid will not separate upon standing.
The particles are constantly colliding, and this allows a colloid to scatter light – thus colloids often seem cloudy.

39. Solutions
A solution is a type of homogeneous mixture formed when one substance dissolves in another.
It is the best mixed of all mixtures.
A solution always has a substance that is dissolved and a substance that does the dissolving.
The substance that is dissolved is the solute and the substance that does the dissolving is the solvent.

40. Ocean water is a solution

41. The universal solvent: Water

42. Water as a solvent Many liquid solutions contain water as the solvent.
Ocean water is basically a water solution that contains many salts.
Body fluids are also water solutions.

43. Metals dissolved in metals are called alloys.
Types of solutions
Solute
Solvent
Example
Gas
Air (oxygen in nitrogen)
Liquid
Soda water (carbon dioxide in water)
Solid
Ocean water (salt in water)
Solid
Gold jewelry (copper in gold)
Metals dissolved in metals are called alloys.

44. Alloys Stainless steel is a mixture of iron and chromium.
Brass is an alloy of copper
and zinc.

45. Mixtures CAN be separated by physical means
Filters (colander)
Heat (saltwater)
Physical separation (m&ms)
Mixtures are broken down into compounds or molecules

46. Can it be separated by physical means?
If the answer is no, the matter is a pure substance.
An element
Or a compound
Compounds can be broken down into elements

47. Elements Elements are the simplest pure substance.
An element can not be changed into a simpler substance by heating or any chemical process.
The smallest particle of an element that has the properties of that element is called an atom.
An atom is the basic building block of matter.
There are more than one hundred known elements in the universe listed on the periodic table of elements.
These elements combine in such a way to create millions of compounds.

48. Elements All elements are made of atoms.
Atoms of the same element are alike.
Atoms of different elements are different.

49. Elements
In 1813, a system of representing elements with symbols was introduced.
Each symbol consists of one or two letters.
Two letters are needed for a chemical symbol when the first letter of that element’s name has already been used.

50. Common Elements Aluminum Al Bromine Br Calcium Ca Carbon C Gold Au
Helium He
Hydrogen H
Nitrogen N

51. Compounds Compounds are also pure substances.
But compounds are made from more than one element.
Water is a compound.
Water can be broken down into simpler substances – hydrogen and oxygen. (heat)

53. Element, Compound, or Mixture?
Rocks

54. Element, Compound, or Mixture?
Rocks

55. Element, Compound, or Mixture?
Copper

56. Element, Compound, or Mixture?
Copper Cu

57. Element, Compound, or Mixture?
Jelly Beans

58. Element, Compound, or Mixture?
Jelly Beans

59. Element, Compound, or Mixture?
Table Sugar

60. Element, Compound, or Mixture?
Table Sugar
C12H22O11

61. Element, Compound, or Mixture?
Diamond

62. Element, Compound, or Mixture?
Diamond C

63. Element, Compound, or Mixture?
Tea

64. Element, Compound, or Mixture?
Tea

65. Element, Compound, or Mixture?
Salt

66. Element, Compound, or Mixture?
Salt
NaCl

67. Element, Compound, or Mixture?
Neon Gas

68. Element, Compound, or Mixture?
Neon Gas Ne

69. Element, Compound, or Mixture?
Salad

70. Element, Compound, or Mixture?
Salad

71. Element, Compound, or Mixture?
Pure Water

72. Element, Compound, or Mixture?
Pure Water
H2O

73. Element, Compound, or Mixture?
Aluminum

74. Element, Compound, or Mixture?
Aluminum Al

75. Element, Compound, or Mixture?
Lemonade

76. Element, Compound, or Mixture?
Lemonade

77. Element, Compound, or Mixture?
Silver

78. Element, Compound, or Mixture?
Silver Ag

79. Element, Compound, or Mixture?
Sand

80. Element, Compound, or Mixture?
Sand

81. Exit Ticket
The number of what component of an atom determines which type of element it is?
What is the main difference between a compound and a mixture?
List some ways or tools that can be used to separate mixtures