Chemistry Unit Test
Science 8(Version B)

Multiple Choice

Select the option that best answers each question.

  1. Because atoms are so small,
  2. they cannot be made of anything smaller.
  3. scientists created models to describe them.
  4. there is no way to observe them.
  5. they cannot be synthesized by scientists.
  6. Scientists’ view of what the atom looks like has
  7. remained constant over time.
  8. changed only once.
  9. been finalized..
  10. changed over time due to new discoveries from advances in technology
  11. The atom is mostly made up of ______.
  12. empty space
  13. protons
  14. neutrons
  15. electrons
  1. This part of the atom has a negative charge.
  2. nucleus
  3. proton
  4. neutron
  5. electron
  1. This part of the atom has a neutral charge.
  2. nucleus
  3. proton
  4. neutron
  5. electron
  1. This part of the atom has a positive charge.
  2. electron
  3. proton
  4. neutron
  5. none of the above
  1. The elements in the periodic table are arranged:
  2. by increasing atomic mass.
  3. alphabetically.
  4. by date of discovery or synthetic preparation.
  5. by increasing atomic number.
  1. The smallest part of an element that still has the properties of that element is called a(n) ______.
  2. compound
  3. atom
  4. mixture
  5. molecule
  6. Each group or family in the Periodic Table has its own characteristic properties based on their common number of ______.
  7. valence electrons
  8. neutrons
  9. protons
  10. ions
  1. Which sub-atomic particles are located in the nucleus of the atom?
  2. Electrons and Neutrons
  3. Protons and Neutrons
  4. Protons and Electrons
  5. Protons, Neutrons and Electrons
  1. In an atom, the number of protons is also equal to the number of
  2. nuclei.
  3. neutrons.
  4. electrons.
  5. isotopes.
  6. The Atomic Mass of an element is based on the
  7. number of neutrons in its nucleus.
  8. number of electrons in the valence shell.
  9. number of protons in its nucleus.
  10. mass of its nucleus.
  11. The Atomic Number of an element is based on the
  12. mass of its nucleus.
  13. number of protons in the nucleus.
  14. number of neutrons in the nucleus.
  15. number of electrons in the electron cloud.
  16. If an atom from the Halogen family (group 17) gains one electron in its valence shell, the atom would then have ______.
  17. 18 valence electrons
  18. 17 valence electrons
  19. 8 valence electrons
  20. 7 valence electrons
  21. From an element’s location on the Periodic Table, you can predict
  22. its name.
  23. its physical and chemical properties.
  24. its chemical symbol.
  25. the year it was discovered.
  26. The electrons involved in chemical bonding between atoms are found
  27. inside the nucleus.
  28. closest to the nucleus.
  29. in the valence shell.
  30. all throughout the electron cloud.
  31. What holds atoms together in a molecule or a compound?
  32. Magnetism
  33. Gravity
  34. Physical bonds
  35. Chemical bonds (i.e. – covalent, ionic, metallic)
  36. What is the main difference between a molecule and a compound?
  37. A molecule is large, while a compound is small.
  38. A molecule is made up of 2 or more atoms, while a compound must be made up of 2 or more different types of atoms.
  39. A molecule can be separated through physical means such as filtration or magnetism.
  40. There is none, molecules and compounds are the same thing.
  41. Identify the compound from the following list.
  42. CO
  43. O2
  44. O3
  45. H2
  46. Which of the following is NOT a compound?
  47. Water (H2O)
  48. Baking soda (NaHCOe)
  49. Sugar (C6H12O6)
  50. Calcium (Ca)
  51. Which of the following is NOT an element found in DNA?
  52. Phosphorous
  53. Helium
  54. Carbon
  55. Oxygen
  56. Which of the following DOES NOT describe the DNA molecule?
  57. DNA is in the shape of a single helix.
  58. DNA is a macromolecule.
  59. DNA has a sugar-phosphate backbone.
  60. DNA is made up of base pairs, A-T and C-G.
  61. An ionic bond is the attraction between
  62. neutral ions.
  63. neutral atoms.
  64. oppositely charged ions.
  65. similarly charged ions.
  66. When an atom gains an electron, it becomes a
  67. negatively charged ion.
  68. positively charged ion.
  69. neutrally charged ion.
  70. neutrally charged atom.
  71. A “cation” is an atom that
  72. is positively charged.
  73. has lost electrons.
  74. will bond with anions to become more stable.
  75. all of the above.
  76. Name the following ionic compound: CaCl2
  77. Calcium dichloride
  78. Carbon dichloride
  79. Calcium chloride
  80. Carbon chloride
  81. What is the chemical formula for the compound “Dinitrogen trioxide?”
  82. 2(NO)3
  83. NO3
  84. N2O3
  85. N2O
  86. Name the following covalent compound: CH4
  87. Carbon hydride
  88. Monocarbon hydride
  89. Monocarbontetrahydride
  90. Carbon tetrahydride
  91. Identify the common name of the compound“Sodium chloride?”
  92. Water
  93. Salt
  94. Vinegar
  95. Baking soda
  96. Identify the number ofoxygen atoms in the following compound: Be(OH)2
  97. 4
  98. 3
  99. 2
  100. 1
  101. When two or more atoms share electrons, a(n) ______is formed.
  102. polyatomic bond
  103. ionic bond
  104. chemical bond
  105. covalent bond
  106. What happens when chemical bonds break and new bonds form?
  107. A physical change.
  108. A chemical reaction.
  109. Matter is destroyed.
  110. Surface area increases.

Use the diagram below to help you answer questions #33-36.

Atoms of Various Common Elements

Element / Atomic Number / Mass Number / Protons / Neutrons / Electrons
Sodium / 11 / ? / 11 / 12 / ?
Magnesium / 12 / 24 / 12 / ? / 12
Aluminum / ? / 27 / 13 / 14 / 13
Phosphorus / 15 / 31 / ? / 16 / 15
  1. What is the total number of electrons in an atom of sodium?
  2. 14
  3. 13
  4. 12
  5. 11
  6. How many neutrons are in an atom of magnesium?
  1. 14
  2. 13
  3. 12
  4. 11
  1. What is the atomic number of aluminum?
  1. 14
  2. 13
  3. 12
  4. 11
  1. How many protons are in an atom of phosphorus?
  1. 31
  2. 16
  3. 15
  4. 14
  1. Identify the reactants in the following equation: 2 Mg + O2  2 MgO.
  2. 2 Mg
  3. O2
  4. 2 Mg + O2
  5. 2 MgO
  6. Which of the following chemical equations correctly represents the formation of water?
  1. H2 + O2  H2O
  2. 2 H2 + O2  2 H2O
  3. H2 + O2  2 H2O
  4. 2 H2 + 2 O2  2 H2O
  1. Which of the following is NOT evidence of a chemical change?
  1. A change in texture.
  2. A change in color.
  3. A change in odor.
  4. A change in temperature.
  1. One example of a physical change is
  1. burning paper.
  2. baking cookies.
  3. dissolving salt in water.
  4. dissolving a metal in acid.
  1. One example of a chemical change is
  1. filtering sand from water.
  2. crushing a can.
  3. boiling water.
  4. burning wood.
  1. Substances that CANNOT be broken down chemically into other substances are
  1. compounds.
  2. elements.
  3. mixtures.
  4. solutions.
  1. The change in which a substance absorbs energy and feels colder is
  1. an exothermic change.
  2. an endothermic change.
  3. aphysical change.
  4. because of a change in mass.
  1. Fireworks exploding in the air and giving off light and heat are an example of a(n)
  1. exothermic change.
  2. endothermic change.
  3. chemical change.
  4. change in mass.
  1. If you heat a liquid and measure the temperature at which it boils, you are measuring a(n) ______.
  1. atomic property
  2. chemical property
  3. physical property
  4. molecular property
  1. If you describe methane as a gas that easily catches on fire, you are describing a ______.
  1. state of matter
  2. physical property
  3. chemical formula
  4. chemical property
  1. You can find the pH of a substance by using
  1. the pH scale.
  2. litmus paper.
  3. a thermometer.
  4. a conductivity tester.
  1. Acids are described as being “corrosive” because they
  1. turn litmus paper blue.
  2. taste bitter when you eat them.
  3. feel slippery when you touch them.
  4. “eataway” at other materials.
  1. Which is a likely use for a base?
  1. As a vitamin in your food.
  2. Etching metals for printing.
  3. Making cleaning supplies, soaps and detergents.
  4. Making foods taste sour.

Use the following diagram to help you answer questions 50-52.

  1. Which of the following substances is neutral?
  1. Lemon
  2. Ammonia
  3. Water
  4. Blood
  1. Which of the following substances is anacid?
  1. Vinegar
  2. Ammonia
  3. Sodium Hydroxide
  4. Water
  1. Which of the following substances is a base?
  1. Milk
  2. Ammonia
  3. Apple Juice
  4. Banana
  1. Which substance would you want to handle with caution?
  1. Hydrochloric acid
  2. Drain Cleaner
  3. Ammonia
  4. All of the above
  1. Lemonade consists of several substance that are NOT chemically combined, so lemonade is classified as a(n) ______.
  1. element
  2. compound
  3. pure substance
  4. mixture
  1. A measure of how well a solute can dissolve in a solvent is known as
  1. the saturation point.
  2. solubility.
  3. acidity.
  4. concentration.
  1. How is a solute different from a solvent in a solution?
  1. The solvent dissolves the solute.
  2. The solute dissolves the solvent.
  3. The solute is always solid, and the solvent is always liquid.
  4. The solute is always liquid, and the solvent is always solid.
  1. When a few spoonful of sugar are mixed into a cup of water, the sugar is the
  1. base.
  2. acid.
  3. solute.
  4. solvent.
  1. Mixtures can be heterogeneous or homogeneous. Which of the following is the identifying trait of a homogeneous mixture?
  1. A mixture in which the individual components are distinguishable in the mixture.
  2. A mixture in which large particles become suspended.
  3. A mixture in which the individual components are evenly distributed throughout, and you cannot see the individual substances.
  4. A mixture in which the large particles settle to the bottom.
  1. The process that separates substances in a heterogeneous mixture through the use of a screen, coffee filter, mesh, etc., is called ______.
  1. Magnetism
  2. Filtration
  3. Chromatography
  4. Evaporation
  1. The best way to separate iron filings from a mixture of iron filings, sand, gravel, salt and water would be by using ______.
  1. Evaporation
  2. Magnetism
  3. Chromatography
  4. Filtration

Chemistry Unit Test (2011-2012)Science 8 (Version B)