Unit 1 Practice Test. Matching

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Unit 1 Practice Test

Matching

Match each item with the correct statement below.

a. proton d. electron

b. nucleus e. neutron

c. atom

____ 1. the smallest particle of an element that retains the properties of that element ____ 2. a negatively charged subatomic particle

____ 3. a subatomic particle with no charge

a. mass number d. atomic mass

b. atomic mass unit e. isotope c. atomic number

____ 4. atoms with the same number of protons, but different numbers of neutrons in the nucleus of an atom ____ 5. the total number of protons and neutrons in the nucleus of an atom

____ 6. the number of protons in the nucleus of an element

____ 7. the weighted average of the masses of the isotopes of an element

____ 8. one-twelfth the mass of a carbon atom having six protons and six neutrons

a. positron d. transuranium element b. alpha particle e. gamma radiation c. beta particle f. transmutation

____ 9. element with atomic number greater than 92 ____ 10. energetic electron from decomposed neutron ____ 11. high-energy photons emitted by a radioisotope

____ 12. particle of charge +1 and mass equal to that of an electron

____ 13. conversion of an atom of one element to an atom of another element

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 14. The smallest particle of an element that retains the properties of that element is a(n) ____.

a. atom c. proton

b. electron d. neutron

____ 15. Dalton's atomic theory included which idea?

a. All atoms of all elements are the same size.

b. Atoms of different elements always combine in one-to-one ratios.

c. Atoms of the same element are always identical.

d. Individual atoms can be seen with a microscope.

____ 16. Which of the following is NOT a part of Dalton's atomic theory?

a. All elements are composed of atoms.

b. Atoms are always in motion.

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c. Atoms of the same element are identical.

d. Atoms that combine do so in simple whole-number ratios.

____ 17. Which of the following was originally a tenet of Dalton's atomic theory, but had to be revised about a century ago?

a. Atoms are tiny indivisible particles.

b. Atoms of the same element are identical.

c. Compounds are made by combining atoms.

d. Atoms of different elements can combine with one another in simple whole number ratios.

____ 18. All atoms are ____.

a. positively charged, with the number of protons exceeding the number of electrons b. negatively charged, with the number of electrons exceeding the number of protons c. neutral, with the number of protons equaling the number of electrons

d. neutral, with the number of protons equaling the number of electrons, which is equal to the number of neutrons

____ 19. The particles that are found in the nucleus of an atom are ____.

a. neutrons and electrons c. protons and neutrons b. electrons only d. protons and electrons

____ 20. The atomic number of an element is the total number of which particles in the nucleus?

a. neutrons c. electrons

b. protons d. protons and electrons

____ 21. The sum of the protons and neutrons in an atom equals the ____.

a. atomic number c. atomic mass b. nucleus number d. mass number ____ 22. All atoms of the same element have the same ____.

a. number of neutrons c. mass numbers b. number of protons d. mass

____ 23. Isotopes of the same element have different ____.

a. numbers of neutrons c. numbers of electrons b. numbers of protons d. atomic numbers ____ 24. The mass number of an element is equal to ____.

a. the total number of electrons in the nucleus

b. the total number of protons and neutrons in the nucleus c. less than twice the atomic number

d. a constant number for the lighter elements

____ 25. Using the periodic table, determine the number of neutrons in O.

a. 4 c. 16

b. 8 d. 24

____ 26. How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain?

a. 50 protons, 50 electrons, 75 neutrons c. 120 neutrons, 50 protons, 75 electrons b. 75 electrons, 50 protons, 50 neutrons d. 70 neutrons, 75 protons, 50 electrons ____ 27. Which of the following statements is NOT true?

a. Atoms of the same element can have different masses.

b. Atoms of isotopes of an element have different numbers of protons.

c. The nucleus of an atom has a positive charge.

d. Atoms are mostly empty space.

____ 28. If E is the symbol for an element, which two of the following symbols represent isotopes of the same element?

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1. E 2. E 3. E 4. E

a. 1 and 2 c. 1 and 4

b. 3 and 4 d. 2 and 3

____ 29. How is the number of neutrons in the nucleus of an atom calculated?

a. Add the number of electrons and protons together.

b. Subtract the number of electrons from the number of protons.

c. Subtract the number of protons from the mass number.

d. Add the mass number to the number of electrons.

____ 30. Which of the following is necessary to calculate the atomic mass of an element?

a. the atomic mass of carbon-12 b. the atomic number of the element

c. the relative masses of the element’s protons and neutrons d. the masses of each isotope of the element

____ 31. The element coppper has naturally occuring isotopes with mass numbers of 63 and 65. the average atomic mass is 64.93. Which of the following is most abundant?

a. Cu-62 c. Cu-63

b. Cu-64 d. Cu-65

____ 32. Nitrogen has two natural occuring isotopes: N-14 and N-15. The average atomic mass of Nitrogen is 14.00674 amu. What is the approximate percentage of N-15?

a. 99 % c. 1%

b. 50 % d. 75 %

____ 33. Which is the most susceptible to damage from ionizing radiation?

a. soft tissue c. wood

b. paper d. lead

____ 34. The charge on a gamma ray is ____.

a. +2 c. 0

b. 1 d. 2

____ 35. The least penetrating form of radiation is ____.

a. beta radiation c. alpha radiation b. gamma radiation d. X rays

____ 36. Ionizing radiation that consists of helium nuclei is ____.

a. X radiation c. beta radiation b. gamma radiation d. alpha radiation

____ 37. What is the change in atomic number when an atom emits a beta particle?

a. decreases by 2 c. increases by 2 b. decreases by 1 d. increases by 1 ____ 38. Which symbol is used for an alpha particle?

a. He c. He

b. He d. He

____ 39. Which of the following materials is necessary to stop a beta particle?

a. three feet of concrete c. thin pieces of wood b. three inches of lead d. single sheet of paper ____ 40. Which type of ionizing radiation can be blocked by clothing?

a. beta radiation c. gamma radiation b. X radiation d. alpha radiation

____ 41. If an isotope decays by the process of beta emission, ____.

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a. the mass number changes b. the atomic number changes c. protons are given off

d. the number of neutrons remains the same

____ 42. What particle is needed to complete this nuclear reaction?

Rn Po + _____

a. He c. H

b. e d. n

____ 43. A transmutation reaction must always involve a(n) ____.

a. change in the number of electrons in the atom

b. decrease in the number of neutrons in the nucleus of an atom c. increase in the number of neutrons in the nucleus of an atom d. change in the number of protons in a nucleus of an atom ____ 44. Matter is not conserved in a nuclear reaction because

a. matter is converted to energy c. matter is converted to gas b. matter is never conserved d. the statement above is false

Short Answer

45. List the number of protons, neutrons, and electrons in C.

46. The element chromium has four naturally occurring isotopes. Use the relative abundance of each to calculate the average atomic mass of chromium.

Cr = 4.34%, Cr = 83.79%, Cr = 9.50%, Cr = 2.37%.

47. If the half-life of a radioactive material is 8 years, how many years will it take for one half of the original amount of material to decay?

48. The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9-g sample of radon-222 would be left after approximately 23 days?

49. The concentration of carbon-14 in a piece of wood from an ancient burial mound indicates that two half-lives of this radioisotope have passed. If the half-life (t ) for carbon-14 is 5730 years, approximately how many years ago did this sample of wood die?

Numeric Response

50. What is the relative charge carried by an electron?

51. What is the relative charge of a proton?

52. Use the periodic table to determine the number of electrons in a neutral atom of lithium.

53. Use the periodic table to determine the number of protons in an atom of barium.

54. What is the total number of subatomic particles in the nucleus of an atom of Bi?

55. Determine the number of electrons in an atom of iridium.

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56. What is the mass number for an oxygen atom that has 10 neutrons in its nucleus?

57. What is the approximate ratio of neutrons to protons for stable atoms below atomic number 20?

58. Above which atomic number are all nuclei radioactive?

59. Above which atomic number are the transuranium elements located?

Essay

60. What observations by Rutherford led to the hypothesis that atoms are mostly empty space, and that almost all of the mass of the atom is contained in an atomic nucleus?

61. Describe alpha particles, beta particles, and gamma rays. Indicate how the atomic number and atomic mass number change when a radioisotope decays to produce alpha, beta, or gamma radiation.

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Unit 1 Practice Test Answer Section

MATCHING

1. ANS: C PTS: 1 DIF: L1 REF: p. 101 | p. 102 OBJ: 4.1.1 | 4.1.2

2. ANS: D PTS: 1 DIF: L1 REF: p. 104

OBJ: 4.2.1

3. ANS: E PTS: 1 DIF: L1 REF: p. 106

OBJ: 4.2.1

OBJ: 4.3.1

5. ANS: A PTS: 1 DIF: L1 REF: p. 111

OBJ: 4.3.1

6. ANS: C PTS: 1 DIF: L1 REF: p. 110

OBJ: 4.3.1

OBJ: 4.3.3

8. ANS: B PTS: 1 DIF: L1 REF: p. 114

OBJ: 4.3.3

OBJ: 25.1.1

OBJ: 25.1.2

13. ANS: F PTS: 1 DIF: L1 REF: p. 807

OBJ: 25.2.3

MULTIPLE CHOICE

14. ANS: A PTS: 1 DIF: L1 REF: p. 101 | p. 102 OBJ: 4.1.1 | 4.1.2

OBJ: 4.1.2

OBJ: 4.2.1

19. ANS: C PTS: 1 DIF: L2 REF: p. 106 | p. 107 OBJ: 4.2.1 | 4.2.2 STA: c4.8A TOP: testout1

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20. ANS: B PTS: 1 DIF: L1 REF: p. 110 OBJ: 4.3.1

OBJ: 4.3.1 STA: C4.8A TOP: testout1

OBJ: 4.3.1 STA: C4.10b TOP: testout1

23. ANS: A PTS: 1 DIF: L1 REF: p. 112 | p. 113 OBJ: 4.3.1

OBJ: 4.3.1

27. ANS: B PTS: 1 DIF: L2 REF: p. 110 | p. 112 | p. 113 OBJ: 4.3.1 STA: C4.8B TOP: testout1

OBJ: 4.3.1 STA: C4.10a, C4.10e TOP: testout1

OBJ: 4.3.2

OBJ: 4.3.3 STA: C4.10c TOP: testout1

31. ANS: D PTS: 1 STA: C4.10d TOP: testout1

32. ANS: C PTS: 1

33. ANS: A PTS: 1 DIF: L1 REF: p. 800 | p. 802 OBJ: 25.1.2

OBJ: 25.1.2

40. ANS: D PTS: 1 DIF: L2 REF: p. 800 | p. 801 | p. 802 OBJ: 25.1.2

OBJ: 25.2.1

OBJ: 25.2.1 STA: c2.r5b TOP: testout1

OBJ: 25.2.3

44. ANS: A PTS: 1 STA: c3.5a TOP: testout1

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SHORT ANSWER

45. ANS:

protons: 6; neutrons: 7; electrons: 6

PTS: 1 DIF: L2 REF: p. 110 | p. 111 OBJ: 4.3.1 | 4.3.2

46. ANS:

50 amu 0.0434 = 2.17 amu 52 amu 0.8379 = 43.57 amu 53 amu 0.0950 = 5.04 amu 54 amu 0.0237 = 1.28 amu _________________________

= 52.06 amu 52 amu

PTS: 1 DIF: L3 REF: p. 116 | p. 117 OBJ: 4.3.3

47. ANS:

8 years

PTS: 1 DIF: L1 REF: p. 804 OBJ: 25.2.2

48. ANS:

23 days/3.8 days = approximately 6 half-lives have passed.

73.9 g (0.5)^6 = 1.2 g remaining.

PTS: 1 DIF: L3 REF: p. 804 | p. 805 OBJ: 25.2.2

49. ANS:

11,460 years ago

PTS: 1 DIF: L3 REF: p. 806 OBJ: 25.2.2

NUMERIC RESPONSE 50. ANS: 1–

PTS: 1 DIF: L1 REF: p. 105 OBJ: 4.2.1 51. ANS: 1+

PTS: 1 DIF: L1 REF: p. 106 OBJ: 4.2.1 52. ANS: 3

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PTS: 1 DIF: L1 REF: p. 808 OBJ: 25.2.3

ESSAY

60. ANS:

Rutherford’s gold-foil experiment led to this hypothesis. Alpha particles were observed to mostly pass through a gold foil, which suggests that the volume of individual gold atoms consists mainly of empty space.

The observation that some alpha particles were scattered at large angles led to the suggestion that the gold atom has a central core, or nucleus, composed of a concentrated mass capable of deflecting the alpha particles.

PTS: 1 DIF: L3 REF: p. 107 OBJ: 4.2.2

61. ANS:

Alpha particles are helium nuclei; they have 2 protons and 2 neutrons. Alpha particles have relatively low energy and are the least penetrating of the three types of ionizing radiation. Beta particles are fast-moving electrons that are intermediate in energy and penetrating power. Gamma rays are electromagnetic radiation in the form of high-energy photons. Alpha particle emission reduces the atomic number of a radioisotope by 2, and the atomic mass number by 4. Beta particle emission increases atomic number by 1 and does not change the atomic mass number. Gamma ray emission neither alters the atomic mass number nor the atomic number.

PTS: 1 DIF: L2 REF: p. 800 | p. 801 | p. 802 OBJ: 25.1.2 | 25.2.1