Study Guide - Chapter 4
True/False
Indicate whether the statement is true or false.
____
1. The modern periodic table is arranged by increasing atomic mass of the elements.
____
2. Aristotle named atoms atoms.
____
3. A cathode ray tube consists of a stream of protons.
____
4. In a neutral atom, the number of protons is equal to the number of neutrons.
____
5. Gamma decay emits energy but no particles.
____
6. An alpha particle is the equivalent of a Helium-4 nucleus.
____
7. Nuclear decay can change one element into another one.
____
8. Isotopes are forms of an element that have the same number of protons but a different number of electrons.
____
9. An input of energy is required in order for nuclear decay to happen in an atom.
____ 10. Gamma decay is a form of nuclear radiation that consists entirely of energy, not matter.
____ 11.
The stability of a nucleus is determined by the ratio of electrons to protons.
____ 12. The mass of a neutron is approximately equal to the mass of a proton.
____ 13. The modern periodic table is arranged from right to left in order of increasing atomic mass.
____ 14. Greek philosophers thought that matter was composed of four elements: air, earth, fire, and water.
____ 15. In the notation
, 107 represents the atomic number and 47 represents the atomic mass of silver.
____ 16. Radon is a radioactive substance that undergoes spontaneous emission of radiation due to its unstable nuclei.
____ 17. Atoms of a radioactive element can change into atoms of another element by emitting radiation.
____ 18. A proton is a subatomic particle carrying a charge equal to but opposite that of an electron.
____ 19. Cathode rays are deflected toward a negatively charged plate in an electric field.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 20. The box for an element from the periodic table is shown. Which is the atomic mass?
a. A
b. B
c. C
d. D
____ 21. The box for an element from the periodic table is shown. Which is the atomic number?
a. A
c. C
b. B
d. D
____ 22. Which scientist described a positively charged core (“nucleus”) in the middle of a lot of empty space?
a. Chadwick
c. Rutherford
b. Thomson
d. Bohr
____ 23. Which scientist described an atom made of a solid positively charged substance with electrons dispersed
throughout it?
a. Chadwick
c. Rutherford
b. Thomson
d. Bohr
____ 24. Which scientist developed the model of the atom shown?
a. Chadwick
b. Thomson
c. Rutherford
d. Bohr
____ 25. Which scientist developed the model of the atom shown?
a. Chadwick
b. Thomson
c. Rutherford
d. Bohr
____ 26. Which scientist described the existence of the neutron?
a. Chadwick
c. Rutherford
b. Thomson
d. Bohr
____ 27. Which one is comprised of the other three?
a. proton
b. atom
c. electron
d. neutron
____ 28. Which has a charge of +1?
a. proton
b. atom
c. electron
d. neutron
____ 29. Which one(s) have a mass of 1 amu?
a. electron
b. proton
c. proton and neutron
d. electron and proton
Atom
1
2
3
4
Atoms
Protons
Neutrons
8
10
10
9
9
9
8
11
____ 30. Which two are isotopes of one another?
a. Atoms 1 & 2
b. Atoms 2 & 3
Electrons
8
10
9
8
c. Atoms 1 & 3
d. Atoms 1 & 4
____ 31. Which two have the same mass?
a. Atoms 1 & 2
b. Atoms 2 & 4
c. Atoms 1 & 4
d. Atoms 2 & 3
____ 32. Which is the smallest part of an element that retains all the properties of the element?
a. proton
c. electron
b. neutron
d. atom
____ 33. Which type of nuclear decay releases the type of particle shown?
a. alpha
b. beta
Atom
Sodium
Chlorine
c. gamma
d. proton
Protons
Atoms
Neutrons
12
17
Electrons
17
Mass Number
23
35
____ 34. How many neutrons are in an atom of chlorine?
a. 17
c. 34
b. 18
d. 35
____ 35. How many electrons are in an neutral atom of sodium?
a. 22
c. 12
b. 11
d. 23
____ 36. What is the mass number of the atom shown?
a. 11
b. 18
c. 19
d. 20
____ 37. Which element does this atom represent?
a. potassium
b. neon
c. fluorine
d. sodium
____ 38. Which is the correct symbol for this atom?
a.
c.
b.
d.
____ 39. Which is the correct symbol for the atom with 42 protons and 49 neutrons?
a.
c.
b.
d.
____ 40. Which is the number of protons in
a. 26
b. 30
____ 41. Which is the number of neutrons in
a. 35
b. 45
____ 42. Which element has 14 protons?
a. Nitrogen
b. Silicon
?
c. 56
d. 82
?
c. 80
d. 115
c. Aluminum
d. Sulfur
____ 43. Which scientist measured the charge on an electron as 1.602 x 10-19 Coulombs?
a. Democritus
c. Rutherford
b. Millikan
d. Bohr
____ 44. According to the modern concept of the atom, which are located in the nucleus of an atom?
a. electrons and protons
c. neutrons and electrons
b. protons only
d. protons and neutrons
____ 45. An atom has 23 protons and 29 neutrons. Which is the correct chemical symbol for this atom?
a.
c.
b.
d.
____ 46. An industrially important element contains 26 electrons and rusts in the presence of air and moisture. Identify
the element.
a. Aluminum
c. Potassium
b. Iron
d. Sodium
____ 47. Who was the man who lived from 460B.C.–370B.C. and was among the first to suggest the idea of atoms?
a. Atomos
c. Democritus
b. Dalton
d. Thomson
____ 48. Which of the following was NOT among Democritus’s ideas?
a. Matter consists of tiny particles called atoms.
b. Atoms are indivisible.
c. Atoms retain their identity in a chemical reaction.
d. Atoms are indestructible.
____ 49. 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.
____ 50. 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.
c. Atoms of the same element are identical.
d. Atoms that combine do so in simple whole-number ratios.
____ 51. 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.
____ 52. The comparison of the number of atoms in a copper coin the size of a penny with the number of people on
Earth is made to illustrate which of the following?
a. that atoms are indivisible
b. that atoms are very small
c. that atoms are very large
d. that in a copper penny, there is one atom for every person on Earth
____ 53. The range in size of most atomic radii is approximately ____.
a. 2 to 5 cm
c. 5 10 m to 2
b. 2 to 5 nm
d. 5 10 m to 2
10
10
m
m
____ 54. Dalton hypothesized that atoms are indivisible and that all atoms of an element are identical. It is now known
that ____.
a. all of Dalton's hypotheses are correct
b. atoms of an element can have different numbers of protons
c. atoms are divisible
d. all atoms of an element are not identical but they must all have the same mass
____ 55. Why did J. J. Thomson reason that electrons must be a part of the atoms of all elements?
a. Cathode rays are negatively-charged particles.
b. Cathode rays can be deflected by magnets.
c. An electron is 2000 times lighter than a hydrogen atom.
d. Charge-to-mass ratio of electrons was the same, regardless of the gas used.
____ 56. Which of the following is true about subatomic particles?
a. Electrons are negatively charged and are the heaviest subatomic particle.
b. Protons are positively charged and the lightest subatomic particle.
c. Neutrons have no charge and are the lightest subatomic particle.
d. The mass of a neutron nearly equals the mass of a proton.
____ 57. Who conducted experiments to determine the quantity of charge carried by an electron?
a. Rutherford
c. Dalton
b. Millikan
d. Thomson
____ 58. What is the relative mass of an electron?
a. 1/1840 the mass of a hydrogen atom
b. 1/1840 the mass of a neutron + proton
c. 1/1840 the mass of a C-12 atom
d. 1/1840 the mass of an alpha particle
____ 59. Which hypothesis led to the discovery of the proton?
a. When a neutral hydrogen atom loses an electron, a positively-charged particle should
remain.
b. A proton should be 1840 times heavier than an electron.
c. Cathode rays should be attracted to a positively-charged plate.
d. The nucleus of an atom should contain neutrons.
____ 60. Which of the following is correct concerning subatomic particles?
a. The electron was discovered by Goldstein in 1886.
b. The neutron was discovered by Chadwick in 1932.
c. The proton was discovered by Thomson in 1880.
d. Cathode rays were found to be made of protons.
____ 61. 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
____ 62. As a consequence of the discovery of the nucleus by Rutherford, which model of the atom is thought to be
true?
a. Protons, electrons, and neutrons are evenly distributed throughout the volume of the atom.
b. The nucleus is made of protons, electrons, and neutrons.
c. Electrons are distributed around the nucleus and occupy almost all the volume of the atom.
d. The nucleus is made of electrons and protons.
____ 63. The nucleus of an atom is ____.
a. the central core and is composed of protons and neutrons
b. positively charged and has more protons than neutrons
c. negatively charged and has a high density
d. negatively charged and has a low density
____ 64. 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
____ 65. What does the number 84 in the name krypton-84 represent?
a. the atomic number
c. the sum of the protons and electrons
b. the mass number
d. twice the number of protons
____ 66. Isotopes of the same element have different ____.
a. numbers of neutrons
c. numbers of electrons
b. numbers of protons
d. atomic numbers
____ 67. Isotopes of the same element have different ____.
a. positions on the periodic table
c. atomic numbers
b. chemical behavior
d. mass numbers
____ 68. In which of the following sets is the symbol of the element, the number of protons, and the number of
electrons given correctly?
a. In, 49 protons, 49 electrons
c. Cs, 55 protons, 132.9 electrons
b. Zn, 30 protons, 60 electrons
d. F, 19 protons, 19 electrons
____ 69. Using the periodic table, determine the number of neutrons in
a. 4
c. 16
b. 8
d. 24
O.
____ 70. 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
____ 71. 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.
____ 72. If E is the symbol for an element, which two of the following symbols represent isotopes of the same
element?
1. E
2. E
3. E
4. E
a. 1 and 2
b. 3 and 4
c. 1 and 4
d. 2 and 3
____ 73. Select the correct symbol for an atom of tritium.
a. n
c.
b. H
d.
H
H
____ 74. Which of the following sets of symbols represents isotopes of the same element?
a.
c.
J
J
J
M
M
M
b.
d.
L
L
L
Q
Q
Q
____ 75. 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.
____ 76. In which of the following is the number of neutrons correctly represented?
a.
c.
F has 0 neutrons.
Mg has 24 neutrons.
b.
As has 108 neutrons.
d.
U has 146 neutrons.
____ 77. How do the isotopes hydrogen-1 and hydrogen-2 differ?
a. Hydrogen-2 has one more electron than hydrogen-1.
b. Hydrogen-2 has one neutron; hydrogen-1 has none.
c. Hydrogen-2 has two protons; hydrogen-1 has one.
d. Hydrogen-2 has one proton; hydrogen-1 has none.
____ 78. Which of the following isotopes has the same number of neutrons as phosphorus-31?
a.
c.
P
Si
b.
d.
S
Si
____ 79. What unit is used to measure weighted average atomic mass?
a. amu
b. gram
c. angstrom
d. nanogram
____ 80. Which of the following equals one atomic mass unit?
a. the mass of one electron
b. the mass of one helium-4 atom
c. the mass of one carbon-12 atom
d. one-twelfth the mass of one carbon-12 atom
____ 81. Which of the following statements is NOT true?
a. Protons have a positive charge.
b. Electrons are negatively charged and have a mass of 1 amu.
c. The nucleus of an atom is positively charged.
d. Neutrons are located in the nucleus of an atom.
____ 82. Why do chemists use relative masses of atoms compared to a reference isotope rather than the actual masses
of the atoms?
a. The actual mass of an electron is very large compared to the actual mass of a proton.
b. The actual masses of atoms are very small and difficult to work with.
c. The number of subatomic particles in atoms of different elements varies.
d. The actual masses of protons, electrons, and neutrons are not known.
____ 83. The atomic mass of an element depends upon the ____.
a. mass of each electron in that element
b. mass of each isotope of that element
c. relative abundance of protons in that element
d. mass and relative abundance of each isotope of that element
____ 84. 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
Matching
Match each item with the correct statement below.
a. proton
d. electron
b. nucleus
e. neutron
c. atom
____ 85. the smallest particle of an element that retains the properties of that element
____ 86. a positively charged subatomic particle
____ 87. a negatively charged subatomic particle
____ 88. a subatomic particle with no charge
____ 89. the central part of an atom, containing protons and neutrons
Match each item with the correct statement below.
a. mass number
d. atomic mass
b. atomic mass unit
c. atomic number
e. isotope
____ 90. atoms with the same number of protons, but different numbers of neutrons in the nucleus of an atom
____ 91. the total number of protons and neutrons in the nucleus of an atom
____ 92. the number of protons in the nucleus of an element
____ 93. the weighted average of the masses of the isotopes of an element
____ 94. one-twelfth the mass of a carbon atom having six protons and six neutrons