Download Chapter 4 test review

Chapter 4 test
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Democritus thought that matter was made of tiny particles
a. of earth, air, fire, and water.
b. that could not be divided.
c. that could be divided.
d. that were all round and smooth.
____
2. If 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of
element Y would combine with 14 grams of X to form the same compound?
a. 7 grams
c. 21 grams
b. 14 grams
d. 28 grams
____
3. Which of the following is NOT part of John Dalton’s atomic theory?
a. All elements are composed of atoms.
b. All atoms of the same element have the same mass.
c. Atoms contain subatomic particles.
d. A compound contains atoms of more than one element.
____
4. Which of the following most accurately represents John Dalton’s model of the atom?
a. a tiny, solid sphere with an unpredictable mass for a given element
b. a hollow sphere with a dense nucleus
c. a tiny, solid sphere with a predictable mass for a given element
d. a sphere that is hollow throughout
____
5. J. J. Thomson’s experiments provided evidence that an atom
a. is the smallest particle of matter.
b. contains negatively charged particles.
c. has a negative charge.
d. has a positive charge.
Figure 4-1
____
6. The diagram in Figure 4-1 shows the results of Rutherford’s gold foil experiment. What caused some of
the alpha particles to bounce straight back from the gold foil?
a. electrons in the gold atoms
c. other alpha particles
b. negative charges in the gold atoms
d. nuclei in the gold atoms
____
7. In an atomic model that includes a nucleus, positive charge is
a. concentrated in the center of an atom.
b. spread evenly throughout an atom.
c. concentrated at multiple sites in an atom.
d. located in the space outside the nucleus.
____
8. Which statement best describes Rutherford’s model of the atom?
a. It is like an avocado with the pit representing the nucleus.
b. It is like an aquarium with swimming fish representing positive charges.
c. It is like a fried egg with the yolk representing the nucleus.
d. It is like a huge stadium with a positively charged marble at the center.
____
9. Which statement about subatomic particles is NOT true?
a. Protons and neutrons have almost the same mass.
b. Protons and electrons have opposite charges.
c. Unlike protons and electrons, neutrons have no charge.
d. Protons and neutrons have the same charge.
____ 10. The number of protons in one atom of an element is that element’s
a. mass number.
c. atomic number.
b. balanced charge.
d. isotope.
____ 11. In Niels Bohr’s model of the atom, electrons move
a. like balls rolling down a hill.
c. like popcorn in a popcorn popper.
b. like planets orbiting the sun.
d. like beach balls on water waves.
____ 12. What does the electron cloud model describe?
a. the most likely locations of electrons in atoms
b. the precise locations of electrons in atoms
c. the number of electrons in an atom
d. the mass of the electrons in an atom
____ 13. Which of the following provides the best analogy for an electron in an atomic orbital?
a. a bee moving from flower to flower in a garden
b. a bird resting on a tree branch
c. an ant crawling on the surface of a leaf
d. a bee trying to escape from a closed jar
____ 14. What is the difference between an atom in the ground state and an atom in an excited state?
a. The atom in the ground state has less energy and is less stable than the atom in an excited
state.
b. The atom in an excited state has one fewer electron than the atom in the ground state.
c. The atom in an excited state has more energy and is less stable than the atom in the ground
state.
d. The atom in an excited state has one more electron than the atom in the ground state.
____ 15. Which subatomic particle has a negative charge?
a. electron
c. neutron
b. alpha particle
d. proton
____ 16. Which statement about subatomic particles is true?
a. Protons, neutrons, and electrons all have about the same mass.
b. Unlike protons or neutrons, electrons have no mass.
c. Neutrons have no charge and no mass.
d. An electron has far less mass than either a proton or neutron.
____ 17. Which of the following is unique for any given element?
a. the number of neutrons
c. the number of protons
b. the charge on the electrons
d. the mass of a neutron
____ 18. To find the number of neutrons in an atom, you would subtract
a. mass number from atomic number.
c. atomic number from electron number.
b. atomic number from mass number.
d. isotope number from atomic number.
____ 19. Which statement is true about oxygen-17 and oxygen-18?
a. They do not have the same number of protons.
b. Their atoms have an identical mass.
c. They are isotopes of oxygen.
d. The have the same mass number.
____ 20. What can you assume has happened if an electron moves to a higher energy level?
a. The atom has become more stable.
c. The electron has gained energy.
b. The electron has lost energy.
d. The atom has lost an electron.
Completion
Complete each statement.
21. The subatomic particle that J. J. Thomson discovered has a(an) ____________________ charge.
22. In Rutherford’s gold foil experiment, some of the _________________________ aimed at gold atoms
bounced back, suggesting that a solid mass was at the center of the atom.
23. The results of Rutherford’s gold foil experiment demonstrated that the ____________________ occupies
a very small amount of the total space inside an atom.
24. Neutrons and ____________________ have almost the same mass.
25. The difference between a sample of heavy water and regular water is that a hydrogen atom in heavy water
has an extra ____________________.
26. Protons and ____________________ are found in the nucleus of an atom.
27. The ____________________ of an isotope is the sum of the number of protons and neutrons in its
nucleus.
Short Answer
28. What scientific word comes from a Greek word meaning “uncut”? Which Greek philosopher first used
the word to describe matter?
29. If an atom of tin has a mass number of 118 and an atomic number of 50, how many neutrons are in its
nucleus?
Essay
30. A sample of calcium contains calcium-40, calcium-44, calcium-42, calcium-48, calcium-43, and calcium46 atoms. Explain why these atoms can have different mass numbers but must have the same atomic
number.