Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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Dalton incorporated the law of conservation of mass into his atomic theory by
asserting that
a. | atoms are indivisible. | b. | atoms of different elements have different
properties. | c. | matter is composed of atoms. | d. | atoms can be destroyed in chemical
reactions. |
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2.
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If each atom of element D has 3 mass units and each atom of element E has 5 mass
units, a molecule composed of one atom each of D and E has
a. | 2 mass units. | c. | 15 mass units. | b. | 8 mass units. | d. | 35 mass units. |
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3.
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If 4.0 g of element A combine with 10. g of element B, then 12 g of element A
combine with ____ g of element B.
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4.
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If 6.0 g of element K combine with 17 g of element L, how many grams of element
K combine with 85 g of element L?
a. | 17 g | c. | 30. g | b. | 23 g | d. | 91 g |
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5.
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In oxides of nitrogen, such as N2O, NO, NO2, and
N2O3, atoms combine in small whole-number ratios. This evidence supports the
law of
a. | conservation of mass. | c. | definite composition. | b. | multiple
proportions. | d. | mass
action. |
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6.
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If two or more compounds are composed of the same two elements, the ratio of the
masses of one element that combine with a fixed mass of the other element is a simple whole number.
This is a statement of the law of
a. | conservation of mass. | c. | multiple proportions. | b. | mass
action. | d. | definite
composition. |
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7.
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Oxygen can combine with carbon to form two compounds, carbon monoxide and carbon
dioxide. The ratio of the masses of oxygen that combine with a given mass of carbon is 1:2. This is
an example of
a. | the law of conservation of mass. | c. | the law of conservation of
energy. | b. | Dalton's atomic theory. | d. | the law of multiple
proportions. |
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8.
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If 63.5 g of copper (Cu) combine with 16 g of oxygen (O) to form the compound
CuO, how many grams of oxygen will be needed to combine with the same amount of copper to form the
compound CuO2?
a. | 16 g | c. | 64 g | b. | 32 g | d. | 127 g |
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9.
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According to the law of definite proportions, any two samples of KCl have
a. | the same mass. | c. | the same melting point. | b. | slightly different
molecular structures. | d. | the
same ratio of elements. |
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10.
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According to the law of conservation of mass, when sodium, hydrogen, and oxygen
react to form a compound, the mass of the compound is ____ the sum of the masses of the individual
elements.
a. | equal to | c. | less than | b. | greater than | d. | either greater than or less
than |
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11.
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What is the ratio of oxygen to carbon when 32 g of oxygen combine with 12 g of
carbon?
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12.
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The principles of atomic theory recognized today were conceived by
a. | Avogadro. | c. | Dalton. | b. | Bohr. | d. | Rutherford. |
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13.
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The law of definite proportions
a. | contradicted Dalton's atomic theory. | b. | agrees with
Dalton's atomic theory. | c. | replaced the law of conservation of
mass. | d. | assumes that atoms of all elements are identical. |
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14.
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According to Dalton's atomic theory, atoms
a. | are destroyed in chemical reactions. | b. | can be divided. | c. | of each element are
identical in size, mass, and other properties. | d. | of different elements cannot
combine. |
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15.
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Which of the following is not part of Dalton's atomic theory?
a. | Atoms cannot be divided, created, or destroyed. | b. | The number of
protons in an atom is its atomic number. | c. | In chemical reactions, atoms are combined,
separated, or rearranged. | d. | All matter is composed of extremely small
particles called atoms. |
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16.
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Dalton's atomic theory agrees with modern atomic theory except for
the statement that
a. | all matter is made up of small particles. | b. | atoms are not
divided in chemical reactions. | c. | atoms of the same element are chemically
alike. | d. | all atoms of the same element have the same mass. |
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17.
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Which of the following statements is true according to modern atomic
theory?
a. | Atoms of the same element may have different masses. | b. | Atoms may be divided
in ordinary chemical reactions. | c. | Atoms can never combine with any other
atoms. | d. | Cathode rays are composed of protons.. |
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18.
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Which concept in Dalton's atomic theory has been modified?
a. | All matter is composed of atoms. | b. | Atoms of different elements have different
properties and masses. | c. | Atoms can combine in chemical
reactions. | d. | Atoms cannot be divided. |
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19.
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The atomic theory proposed by Dalton has been
a. | totally discarded. | c. | accepted unchanged to the present day. | b. | expanded and
modified. | d. | found to be
plagiarized. |
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20.
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In early experiments on electricity and matter, an electrical current was passed
through a glass tube containing
a. | water. | c. | liquid oxygen. | b. | gas under high pressure. | d. | gas under low
pressure. |
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21.
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In a glass tube attached to a voltage source, electrical current passes from the
negative electrode, called the ____, to the other electrode.
a. | cathode | c. | electron | b. | anode | d. | millikan |
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22.
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When an electrical current passed through a glass tube, it caused the surface of
the tube directly across from the cathode to glow. Scientists concluded that
a. | a magnetic field was produced. | b. | the particles of the beam were negatively
charged. | c. | there was gas in the tube. | d. | atoms were
indivisible. |
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23.
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The rays produced in a cathode tube are
a. | unaffected by a magnetic field. | c. | found to carry a positive
charge. | b. | deflected away from a negative plate. | d. | striking the
cathode. |
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24.
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Experiments with cathode rays led to the discovery of the
a. | proton. | c. | neutron. | b. | nucleus. | d. | electron. |
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25.
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After measuring the ratio of the charge of a cathode-ray particle to its mass,
Thomson concluded that the particles
a. | had no mass. | c. | had a very large mass. | b. | had a very small
mass. | d. | carried a positive
charge. |
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26.
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Because any element used in the cathode produced electrons, scientists concluded
that
a. | all atoms contained electrons. | c. | atoms were
indivisible. | b. | only metals contained electrons. | d. | atoms carried a negative
charge. |
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27.
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The deflection of cathode rays in Thomson's experiments was evidence of the
____ nature of electrons.
a. | wave | c. | particle | b. | charged | d. | spinning |
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28.
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Whose series of experiments identified the nucleus of the atom?
a. | Rutherford | c. | Chadwick | b. | Dalton | d. | Bohr |
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29.
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In Rutherford's experiments, alpha particles
a. | passed through a tube containing gas. | c. | collided with
electrons. | b. | were used to bombard a cathode plate. | d. | were used to bombard thin metal
foil. |
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30.
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In Rutherford's experiments, most of the particles
a. | bounced back. | c. | were absorbed by the foil. | b. | passed through the
foil. | d. | combined with the
foil. |
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31.
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Because most particles fired at metal foil passed straight through, Rutherford
concluded that
a. | atoms were mostly empty space. | c. | electrons formed the
nucleus. | b. | atoms contained no charged particles. | d. | atoms were
indivisible. |
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32.
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Because a few alpha particles bounced back from the foil, Rutherford concluded
that they were
a. | striking electrons. | b. | indivisible. | c. | repelled by densely
packed regions of positive charge. | d. | magnetic. |
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33.
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Rutherford's experiments led him to conclude that atoms contain massive
central regions that have
a. | a positive charge. | c. | no charge. | b. | a negative charge. | d. | both protons and
electrons. |
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34.
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A positively charged particle with mass 1.673 ´
10–24 g is a(n)
a. | proton. | c. | electron. | b. | neutron. | d. | positron. |
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35.
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A nuclear particle that has about the same mass as a proton, but with no
electrical charge, is called a(n)
a. | nuclide. | c. | electron. | b. | neutron. | d. | isotope. |
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36.
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The nucleus of an atom has all of the following characteristics except
that it
a. | is positively charged. | b. | is very dense. | c. | contains nearly all
of the atom's mass. | d. | contains nearly all of the atom's
volume. |
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37.
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Which part of an atom has a mass approximately equal to 1/2000 of the mass of a
common hydrogen atom?
a. | nucleus | c. | proton | b. | electron | d. | neutron |
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38.
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Protons within a nucleus are attracted to each other by
a. | the nuclear force. | c. | their energy levels. | b. | opposite charges. | d. | electron
repulsion. |
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39.
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An atom is electrically neutral because
a. | neutrons balance the protons and electrons. | b. | nuclear forces
stabilize the charges. | c. | the numbers of protons and electrons are
equal. | d. | the numbers of protons and neutrons are equal. |
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40.
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Nuclear forces exists because the particles in the nucleus are
a. | oppositely charged. | c. | highly energized. | b. | close together. | d. | moving very
fast. |
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41.
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Most of the volume of an atom is occupied by the
a. | nucleus. | c. | electrons. | b. | nuclides. | d. | protons. |
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42.
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The charge due to the electrons of a neutral atom
a. | prevents compounds from forming. | c. | attracts electrons in other
atoms. | b. | balances the charge on the nucleus. | d. | does not exist. |
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43.
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The smallest unit of an element that can exist either alone or in combination
with other such particles of the same or different elements is the
a. | electron. | c. | neutron. | b. | proton. | d. | atom. |
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44.
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The radius of an atom extends to the outer edge of the
a. | nucleus. | c. | region occupied by the neutrons. | b. | region occupied by
the electrons. | d. | positive
charges. |
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45.
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Isotopes are atoms of the same element that have different
a. | principal chemical properties. | c. | numbers of
protons. | b. | masses. | d. | numbers of electrons. |
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46.
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The most common form of hydrogen has
a. | no neutrons. | c. | two neutrons. | b. | one neutron. | d. | three neutrons. |
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47.
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The tritium atom consists of
a. | one proton, two neutrons, and two electrons. | b. | one proton, one
neutron, and one electron. | c. | one proton, two neutrons, and one
electron. | d. | two protons, one neutron, and one electron. |
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48.
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What is the mass number of deuterium?
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49.
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How many isotopes of hydrogen are known?
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50.
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The hydrogen isotope with the least mass is named
a. | tritium. | c. | deuterium. | b. | helium. | d. | protium. |
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51.
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The nucleus of deuterium contains one proton and
a. | two neutrons. | c. | no neutrons. | b. | one neutron. | d. | two electrons. |
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52.
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All isotopes of hydrogen contain
a. | one neutron. | c. | one proton. | b. | two electrons. | d. | two nuclei. |
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53.
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The atomic number of oxygen, 8, indicates that there are eight
a. | protons in the nucleus of an oxygen atom. | b. | oxygen
nuclides. | c. | neutrons outside the oxygen atom's nucleus. | d. | energy levels in the
oxygen atom's nucleus. |
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54.
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The total number of protons and neutrons in the nucleus of an atom is its
a. | atomic number. | c. | mass number. | b. | Avogadro number. | d. | average atomic
mass. |
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55.
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As the mass number of an element’s isotopes of an element increases, the
number of protons
a. | decreases. | b. | increases. | c. | remains the
same. | d. | doubles each time the mass number increases. |
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56.
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As the atomic number increases, the number of electrons in a neutral atom
a. | decreases. | c. | remains the same. | b. | increases. | d. | is
undetermined. |
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57.
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All atoms of the same element have the same
a. | atomic mass. | c. | mass number. | b. | number of neutrons. | d. | atomic number. |
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58.
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Atoms of the same element can differ in
a. | chemical properties. | c. | atomic number. | b. | mass number. | d. | number of protons and
electrons. |
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59.
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In determining the atomic mass of elements, the standard is the
a. | C-12 atom. | c. | H-1 atom. | b. | C-14 atom. | d. | O-16 atom. |
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60.
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The relative atomic mass of an atom can be found by comparing the mass of the
atom to the mass of
a. | one atom of carbon-12. | c. | a proton. | b. | one atom of hydrogen-1. | d. | uranium-235. |
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61.
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The carbon-12 atom is assigned a relative mass of exactly
a. | 1 amu. | c. | 12 amu. | b. | 6 amu. | d. | 100 amu. |
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62.
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The average atomic mass of an element is the average of the atomic masses of
its
a. | naturally occurring isotopes. | c. | radioactive
isotopes. | b. | two most abundant isotopes. | d. | artificial isotopes. |
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63.
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The average atomic mass of an element
a. | is the mass of the most abundant isotope. | b. | may not equal the
mass of any of its isotopes. | c. | cannot be calculated. | d. | always adds up to
100. |
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64.
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The atomic mass of an element listed in the periodic table is the
a. | average atomic mass. | b. | relative atomic mass of the most abundant
isotope. | c. | relative atomic mass of the most abundant radioactive isotope. | d. | mass number of the
least abundant isotope. |
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65.
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An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its
mass number is
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66.
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Chlorine has atomic number 17 and mass number 35. It has
a. | 17 protons, 17 electrons, and 18 neutrons. | b. | 35 protons, 35
electrons, and 17 neutrons. | c. | 17 protons, 17 electrons, and 52
neutrons. | d. | 18 protons, 18 electrons, and 17 neutrons. |
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67.
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Carbon-14 (atomic number 6), the radioactive nuclide used in dating fossils,
has
a. | 6 neutrons. | c. | 10 neutrons. | b. | 8 neutrons. | d. | 14 neutrons. |
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68.
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Phosphorus-33 (atomic number 15) contains
a. | 33 protons. | c. | 33 neutrons. | b. | 18 neutrons. | d. | 18 protons. |
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69.
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Neon-22 contains 12 neutrons. It also contains
a. | 12 protons. | c. | 22 electrons. | b. | 22 protons. | d. | 10 protons. |
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70.
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The number of atoms in 1 mol of carbon is
a. | 6.022 ´ 1022. | c. | 5.022 ´ 1022. | b. | 6.022 ´
1023. | d. | 5.022
´ 1023. |
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71.
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The number of atoms in a mole of any pure substance is called
a. | its atomic number. | c. | its mass number. | b. | Avogadro's constant. | d. | its gram-atomic
number. |
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72.
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The atomic number of neon is 10. The atomic number of calcium is 20. Compared
with a mole of neon, a mole of calcium contains
a. | twice as many atoms. | c. | an equal number of atoms. | b. | half as many
atoms. | d. | 20 times as many
atoms. |
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73.
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To determine the molar mass of an element, one must know the
element's
a. | Avogadro constant. | c. | number of isotopes. | b. | atomic number. | d. | average atomic
mass. |
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74.
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Avogadro's number is
a. | the maximum number of electrons that all the energy levels can
accommodate. | b. | the number of protons and neutrons that can fit in the shells of the
nucleus. | c. | the number of particles in 1 mole of a pure substance. | d. | the number of
particles in exactly 1 gram of a pure substance. |
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75.
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Molar mass
a. | is the mass in grams of one mole of a substance. | b. | is numerically equal
to the average atomic mass of the element. | c. | Both (a) and (b) | d. | Neither (a) nor
(b) |
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76.
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The mass of 1 mol of chromium (atomic mass 51.996 amu) is
a. | 12 g. | c. | 51.996 g. | b. | 198 g. | d. | 6.02 ´
1023 g. |
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77.
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The mass of 2.0 mol of oxygen atoms (atomic mass 16.00 amu) is
a. | 16 g. | c. | 48 g. | b. | 32 g. | d. | 64 g. |
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78.
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The mass of a sample containing 3.5 mol of silicon atoms (atomic mass 28.0855
amu) is approximately
a. | 28 g. | c. | 72 g. | b. | 35 g. | d. | 98 g. |
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79.
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How many moles of atoms are in 50.15 g of mercury (atomic mass 200.59
amu)?
a. | 0.1001 mol | c. | 0.2500 mol | b. | 0.1504 mol | d. | 0.4000 mol |
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80.
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A prospector finds 39.39 g of pure gold (atomic mass 196.9665 amu). She
has
a. | 1.204 ´ 1023 atoms of Au. | c. | 4.306 ´ 1023 atoms of Au. | b. | 2.308 ´ 1023 atoms of Au. | d. | 6.022 ´
1023 atoms of Au. |
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81.
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A sample of tin (atomic mass 118.71 amu) contains 3.01 ´ 1023 atoms. The mass of the sample is
a. | 3.01 g. | c. | 72.6 g. | b. | 59.3 g. | d. | 11 g. |
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82.
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The mass of 5.000 mol of cesium (atomic mass 132.9 amu) is
a. | 664.5 g. | c. | 6.022 ´ 1023
g. | b. | 132.9 g. | d. | 5.000 g. |
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Short Answer
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83.
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Describe the law of definite proportions.
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84.
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What is the law of conservation of mass?
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85.
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What is the law of multiple proportions?
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86.
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Describe the nucleus of an atom.
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87.
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Give the location and relative charge of a proton.
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88.
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What is the atomic number of an atom?
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89.
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What is the mass number of an atom?
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90.
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What is an isotope?
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91.
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What is the relationship between isotopes, mass number, and neutrons?
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92.
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Why do chemists work with moles instead of individual atoms?
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Problem
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93.
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How many atoms are present in 8.00 mol of chlorine atoms?
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94.
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How many moles of platinum are equivalent to 1.20 ´ 1024 atoms?
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95.
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How many moles of iron are equivalent to 1.11 ´
1025 atoms?
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96.
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Determine the mass in grams of 10.0 mol of bromine. The molar mass of bromine is
79.90 g/mol.
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97.
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Determine the number of moles of helium in 10.0 g of helium. The molar mass of
helium is 4.00 g/mol.
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98.
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Determine the number of moles in 100. g of potassium. The molar mass of
potassium is 39.10 g/mol.
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99.
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The mass of 1 mol of gold atoms is 196.97 g. Find the mass of 1 atom of
gold.
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100.
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Calculate the number of atoms in 10.0 g of sulfur (molar mass 32.07
g/mol).
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