1. What is chemistry? “Chemistry is the study of the composition, structure, and the properties of matter and the changes it undergoes.” from Modern Chemistry All chemical reactions involve energy.

2. Chemistry – Matter Unit What is matter? What is chemistry? What is the organization of matter? What is the nature of matter?

3. Is Air matter? What are the two criteria for matter? –Does it take up space? –Does it have mass?

4. What is the composition of matter? Matter Pure Matter Substance Impure Matter Mixture

5. What is a pure substance? A pure substance has a definite composition (proportion). The composition of a substance will have the same percent of elements no matter where the sample was obtained. – Water from the White River and water from the Pacific Ocean (once cleaned up) will have the same composition of hydrogen to oxygen. –Gold is the same as other gold (once cleaned up).

6. What is a pure substance? A pure substance, by definition, is an element or a compound. A container with an almost pure compound:

7. Pure Substance Element Compound

8. What is an element? “a pure substance made of only one kind of atom” from Modern Chemistry A substance that cannot be decomposed any farther by simple chemical means An element has a definite composition. Gold from South Africa is the same, when purified, as a sample from California.

9. Periodic Table of Elements Most elements on the periodic chart are metals. Elements through 114 but not 113 have been discovered or made.

10. Elemental Samples Zinc, copper, lead, carbon, sulphur

11. What is a compound? “A compound is a substance that is made from the atoms of two or more elements that are chemically bonded.” From Modern Chemistry The definition is actually more involved than this.

12. What is a compound? A compound is a substance that cannot be decomposed any farther by simple physical means. A compound has a definite composition by mass. A compound is made up of two or more elements chemically combined.

13. What is a compound? A compound no longer has the properties of its constituent elements. Table salt, NaCl or sodium chloride, is a compound of the element sodium and the element chlorine.

14. Sodium

15. Sodium metal Soft, can be cut with a knife Shiny Good conductor of electricity Very reactive

16. Sodium in water

17. Chlorine gas

18. Greenish gas Poisonous Heavier than air

19. Sodium in chlorine gas

20. Sodium chloride, NaCl Sodium chloride dissolves in water rather than reacts with water. Sodium chloride is a white solid, not a poisonous green gas. Sodium chloride is its own substance with its own properties, not those of either sodium or chlorine.

21. Samples of Other Compounds Sucrose (table sugar), Sodium Chloride, Water, Copper(II) sulfate

22. Coloured Compounds Cobalt(II) chloride, Iron(II) sulfate, Potassium dichromate, Potassium chromate, Nickel(II) nitrate, copper(II) sulfate

23. What is the composition of matter? Matter Pure SubstanceImpure Matter Mixture

24. Impure Matter - Mixture “A mixture is a blend of two or more kinds of matter, each of which retains its own identity and properties.” from Modern Chemistry A mixture is made up of two or more substances that are not chemically combined.

25. Mixtures Mixtures can be separated by simple physical means. Two mixtures containing the same substances may not have the same proportions. Example: Very salty water versus barely salty water. Very sweet sugar water versus slightly sweet sugar water.

26. Water and Dye Mixture Two mixtures of the same substances may have different proportions.

27. Mixtures Homogeneous Mixture Heterogeneous Mixture ?

28. Homogeneous Mixture Homogeneous mixtures are uniform in composition. They have the same proportion of components throughout. Homogeneous mixtures are called solutions. Salt water is an example. Solute + solvent = solution

29. H. W Examples of solutions g-g g-l s-s

30. Heterogeneous Mixture Heterogeneous mixtures are not uniform throughout. Clay particles in water are an example. Starch in water

31. Heterogeneous Mixtures Sand and water on the left and sand and gravel on the right.

32. Heterogeneous Mixture

33. Particle Size The particle size for homogeneous and heterogeneous mixtures is defined. –The solute particles for homogeneous mixtures are so small that they cannot be seen. –Heterogeneous mixture particles are visible.

34. Particle Size If the particles are spread evenly throughout the mixture but are not quite but almost visible, a colloidal suspension exists. An actual particle size is defined to differentiate among homogeneous mixtures, heterogeneous mixtures, and colloidal suspensions.

35. Colloidal Suspension Fog

36. Tyndall Effect

37. Examples of solutions and colloids CategoriesSolutionsColloids Solid in liquid Salt water Sugar water Gelatin (jello), paint, clays Solid in gas Smoke Solid in solid Alloys (steel, bronze, brass) Black diamond

38. Examples of solutions and colloids ExamplesSolutionsColloids Liquid in liquid Alcohol in waterMilk (emulsion), mayonnaise Liquid in gas Fog (aerosol), Liquid in solid Mercury in silver and tin Butter, cheese

39. Examples of solutions and colloids CategoriesSolutionsColloids Gas in gas Air Gas in liquid Carbonated water Whipped cream (foam) Gas in solid Marshmallow, polystyrene foam

40. Mixtures vs. Compounds Rocks are mixtures. Minerals are pure substances Granite rock

41. Mixtures vs Compounds Minerals are pure substances although many have impuities that must be cleaned up first.

42. Minerals Amethyst Halite Diamond

43. What is the nature of matter? An atom is the smallest unit of an element that maintains the properties of that element. From Modern Chemistry –An atom is made up of electrons, protons, and neutrons as well as other particles. Protons and neutrons are made up of quarks.

44. What is the nature of matter? A molecule is a unit that consists of more than one atom bonded together. A molecule can have atoms of the same element such as oxygen. These are called diatomic elements.

45. Blue – diatomic elements Diatomic elements – blue Tetraatomic element – red Octatomic element - yellow

46. What is the nature of mature? A molecule can have atoms of more than one type of element. Water Sugar (sucrose)

47. Atoms and Molecules Three particles: –2 atoms of hydrogen –1 atom of oxygen One particle: –1 molecule of water

48. Atoms How can an atom of an element be broken up into atoms of other elements or into other smaller particles and energy? Nuclear Reaction

49. Compound How is a compound broken up into its elements or other simpler compounds? –Use a chemical separation method. What are some examples of chemical separation methods?

50. Chemical Separation Methods Heat the compound.

51. Chemical Separation Methods Use Electrolysis which is using an electric current to decompose the compound. An electrolyte has been added to the water since water does not conduct.

52. Mixtures How can mixtures be separated? –Use Physical Separation Methods. What are examples of physical separation methods?

53. Physical Separation Methods Distillation is the separation of mixtures by using the difference in boiling points of liquids. A water cooled condenser is used.

54. Physical Separation Methods Filtration uses the difference in particle size to separate mixtures. Filter papers have different size pores.

55. Physical Separation Methods Chromatography uses the difference in solubility in various solvents. Gas, liquid, thin layer, and paper chromatography are widely used.

56. States of Matter Three states of matter: Liquid, solid, gas

57. Physical Changes During physical changes matter changes in appearance without forming new substances. What some examples of physical changes?

58. Physical Change Examples Breaking or tearing

59. Physical Change Examples Boiling or condensing

60. Physical Change Examples Freezing or melting

61. Physical Change Examples Sublimation

62. Physical Change Examples Sublimation: “The change of state directly to a gas is known as sublimation.” “The reverse process is called deposition, the change of state from a gas directly to a solid.” From Modern Chemistry

63. Chemical Changes During chemical changes new substances are formed with different properties than the original substances. What is an example of a chemical change?

64. Chemical Change Example Heating baking soda, sodium hydrogen carbonate, forms sodium carbonate, carbon dioxide, and water. The formation of carbon dioxide is what causes cakes to rise.

65. Mixture or Pure Substance These bottles contain sodium chloride, sucrose, and a mixture of the two. Which is which and how can they be identified?

66. Physical and Chemical Properties What are some physical properties of this pen?

67. Physical Properties Examples: –Color –Hardness –Texture –Volume –Length –Mass

68. Physical Properties More Examples: –Density (mass/volume ratio) –Odor –Sound –Boiling point –Melting point –Magnetism

69. Physical Properties Melting Point and freezing point temperatures are the same.

70. Chemical Properties A chemical property is how something reacts. Does the pen float is physical. Does the pen dissolve is physical. Does the pen react with water is chemical.

71. Chemical Properties Does the pen burn is a chemical property. Whether and how something reacts is chemical.

72. Extensive vs Intensive Extensive Properties depend upon the amount of matter that is present. Intensive Properties do not depend on the amount of matter present. These properties are the same for a given substance regardless of how much of the substance is present. From Modern Chemistry

73. Extensive vs Intensive Which of the properties listed earlier are extensive and which are intensive? Comparisons of several properties are used together to identify an unknown.

74. Chemistry Vocabulary A Symbol is a representation of an element. One or two letters may be used. The first letter is upper case while the second is lower case. H C O Fe Cl Ag Cu Ba Cf

75. Chemistry Vocabulary A formula is a representation of a molecule of an element or a molecule of a compound.

76. Chemistry Vocabulary The subscript represents the number of atoms of a particular element in the molecule. 12 atoms of carbon 22 atoms of hydrogen 11 atoms of oxygen

77. Chemistry Vocabulary If no subscript is shown. An understood one is indicated. 2 atoms of hydrogen 1 atom of sulfur 4 atoms of oxygen

78. Chemistry Vocabulary A coefficient is a number in front of a formula and represents the number of molecules. If no coefficient is shown, one molecule is indicated. 2 molecules of sucrose 24 atoms of carbon 44 atoms of hydrogen 22 atoms of oxygen

79. Chemistry Vocabulary An equation is a sentence showing what is happening in a chemical reaction.

80. Chemistry Vocabulary The reactants are the substances (elements or compounds) that will react. They are on the left or starting side.

81. Chemistry Vocabulary The products on the right side of the equation are what are formed or are produced during the reaction.

82. Chemistry Vocabulary An atom is the smallest unit of an element that maintains the properties of that element. From Modern Chemistry –An atom is made up of electrons, protons, and neutrons as well as other particles. Protons and neutrons are made up of quarks.

83. Chemistry Vocabulary A atom is made up of a nucleus and particles outside the nucleus called electrons. Electrons are negatively charged particles. The mass of an electron is about 1800 times smaller than that of the proton and neutron.

84. Chemistry Vocabulary The nucleus is the tiny positive core of the atom. Two of the particles in the nucleus are the proton and the neutron. The proton is a positively charged particle.

85. Chemistry Vocabulary What is wrong with this commonly used picture? The nucleus is 1/10000 times smaller than the atom. The atom is mostly empty space.

86. Chemistry Vocabulary Proton: –The charge on a proton is equal in magnitude but opposite in sign to the charge on an electron. A proton is made up of three quarks. –Two quarks have a +2/3 charge. –One quark has a -1/3 charge.

87. Chemistry Vocabulary The mass of a proton is approximately 1800 times heavier than an electron. ***The number of protons present is what determines the type of atom.*** –If the number of protons change, an atom of a different element is formed.

88. Chemistry Vocabulary The number of protons found in the nucleus is known as the atomic number. –Hydrogen with an atomic number of 1 has only one proton. If it had 2, it would be helium. –Uranium with an atomic number of 92 has 92 protons.

89. Chemistry Vocabulary A neutron is an uncharged particle found in the nucleus. The mass of a neutron is almost the same as the mass of a proton. A neutron is made of three quarks. –One quark has a +2/3 charge. –Two quarks have a -1/3 charge.

90. Chemistry Vocabulary Two atoms of the same element can have differing numbers of neutrons. These are called isotopes. Hydrogen has three isotopes: –Hydrogen with 1 proton and 0 neutrons –Deuterium with 1 proton and 1 neutron –Tritium with 1 proton and 2 neutrons

91. Chemistry Vocabulary The different masses of these isotopes give them different properties such as melting and boiling points and reactivities and stabilities. Regular uranium is not radioactive enough for a nuclear fuel. Only certain isotopes of uranium will work.

92. Chemistry Vocabulary The mass number is the total number of protons and neutrons in the nucleus of the atom. The mass number is not found on the periodic table. The masses on the table are the weighted averages of the isotopes.

93. Chemistry Vocabulary ParticleSymbolChargeMass Number Electron1-0 Proton1+1 Neutron01

94. Chemistry Vocabulary Nuclear Symbol: Mass Number –Number of protons and neutrons Atomic number –Number of protons –Found on Periodic Table

95. Chemistry Vocabulary Number of protons = 17 Number of neutrons = 18 Number of electrons= 17 The number of protons = number of electrons

96. Chemistry Vocabulary Number of protons = 12 Number of neutrons = 13 Number of electrons= 12

97. Chemistry Vocabulary In a neutral atom the number of protons is equal to the number of electrons. The number of protons can never vary in an atom. The electrons are the particles that can be gained or lost in a reaction.

98. Chemistry Vocabulary The sum of the positive protons and the negative electrons give the overall charge of the atom. The term charge was once called valence. The charge is shown as a superscript to the upper right.

99. Chemistry Vocabulary Number of protons = 17 Number of neutrons = 19 Number of electrons= 18 (17+) + (?-) = 1- –So ? = 18-

100. Chemistry Vocabulary Number of protons = 12 Number of neutrons = 12 Number of electrons= 10 (12+) + (?-) = 2+ –?- = 10

101. Chemistry Vocabulary An ion is a charged atom or group of atoms. A cation is a positively charged ion. An anion is a negatively charged ion. The prefix an- can mean not or negative.

102. Chemistry Vocabulary Free state – The atom or molecule is not combined with atoms of other elements. –Gold can be found in the free state. –Because of its reactivity, sodium cannot. Combined state – The atom is part of a compound.

103. Matter Unit Now it is time to try “Chemistry Vocabulary Worksheet: Application of Matter”. The exam will cover the material in this unit, the lab safety material, and the lab drawer equipment. Know the examples and how the ideas go together. Know all parts of the definitions.