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1 | |
What important conclusion was reached through the study of cathode rays? |
| | A) | Cathode rays were proved to be light rays indicating that atoms were indeed indivisible. |
| | B) | Cathode rays were shown to be positively charged particles indicating that atoms contained electric charge. |
| | C) | Cathode rays were shown to be negatively charged particles. |
| | D) | The ratio of the charge to mass ratio of particles making up cathode rays was constant, indicating they were fundamental particles found in all matter. |
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2 | |
How did Thompson establish whether or not cathode rays were light? |
| | A) | He could tell by visual observation. |
| | B) | Thompson knew light rays would be deflected by electric or magnetic fields and he determined experimentally that they were not deflected. |
| | C) | Thompson knew light rays would not be deflected by electric or magnetic fields and he determined experimentally that the rays were deflected. |
| | D) | He determined experimentally if the rays would be deflected by gravity; light rays would not be deflected. |
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3 | |
After the existence of the electron was established by Thompson, Millikan's contribution added what additional information to atomic theory? Millikan |
| | A) | proved electrons had a variable charge. |
| | B) | measured the fixed negative charge of the electron. |
| | C) | proposed the existence of protons. |
| | D) | None of the above. |
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4 | |
After the mass and charge of the electron was known, the next breakthrough in the development of atomic theory was made by Rutherford. What important result was established by Rutherford? |
| | A) | The atom was of uniform substance containing electrons arranged like raisins in plum pudding. |
| | B) | Rather than being spread out, electrons occupied one half of an atom and the positive charges occupied the other half. |
| | C) | Electrons disappeared inside an atom. They only existed outside. |
| | D) | All positive charge in an atom was concentrated at a tiny part of the center. |
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5 | |
What new concept did Bohr adapt and use to formulate his model of the atom? |
| | A) | The quantum concept developed by Planck. |
| | B) | Electromagnetic theory developed by Maxwell. |
| | C) | Photoelectric theory developed by Thompson. |
| | D) | Neutron theory developed by Chadwick. |
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6 | |
What basis did Bohr have for allowing only specific orbits for electrons in his model of the atom? |
| | A) | Specific orbits were proven experimentally. |
| | B) | Bohr assumed only specific orbits were allowed. |
| | C) | Allowed orbits were predicted from electromagnetic theory. |
| | D) | It was the general consensus of the scientific community. |
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7 | |
The idea that electrons have wave properties |
| | A) | was never proved and is now discounted. |
| | B) | was only proved theoretically. |
| | C) | was proved experimentally. |
| | D) | is true, but of no consequence. |
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8 | |
Quantum mechanics considers electron energy levels in an atom and identifies those levels with four quantum numbers. The first, the principal quantum number considers what property of an electron? |
| | A) | energy sublevel |
| | B) | distance from the nucleus |
| | C) | orientation in space |
| | D) | direction of spin |
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9 | |
The second, or angular momentum quantum number, considers what property? |
| | A) | energy sublevel |
| | B) | distance from the nucleus |
| | C) | orientation in space |
| | D) | direction of spin |
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10 | |
The third quantum number, the magnetic quantum number, considers what property? |
| | A) | energy sublevel |
| | B) | distance from the nucleus |
| | C) | orientation in space |
| | D) | direction of spin |
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11 | |
The fourth quantum number, the spin quantum number, considerers what property? |
| | A) | energy sublevel |
| | B) | distance from the nucleus |
| | C) | orientation in space |
| | D) | direction of spin |
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12 | |
The distribution of electrons in an atom is specified by the quantum numbers of each electron. What important principle governs the assignment of quantum numbers to electrons in an atom? |
| | A) | The Schrodinger inclusion principle states that quantum numbers must be assigned to all available electrons. |
| | B) | The Heisenberg uncertainty principle states that the exact position and momentum of an electron cannot be determined at the same time. |
| | C) | The Pauli exclusion principle states that no two electrons in an atom can have the same four quantum numbers. |
| | D) | None of the above. |
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13 | |
Isotopes are atoms of an element with identical |
| | A) | masses but different abundances. |
| | B) | masses but different chemical properties. |
| | C) | chemical properties but different masses. |
| | D) | abundances but different masses. |
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14 | |
The weighted average of the masses of stable isotopes of an element as they occur in nature is called the |
| | A) | average atomic mass. |
| | B) | atomic weight. |
| | C) | atomic mass. |
| | D) | atomic mass unit. |
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15 | |
The isotope used as a standard for measuring atomic masses is |
| | A) | carbon-12. |
| | B) | carbon-14. |
| | C) | hydrogen-1. |
| | D) | oxygen-16. |
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16 | |
The mass of the carbon-12 isotope is |
| | A) | 12.00 grams. |
| | B) | 1.00 grams. |
| | C) | 1.00 units. |
| | D) | 12.00 units. |
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17 | |
The atomic number identifies the total number of |
| | A) | particles in an atom. |
| | B) | protons in the nucleus. |
| | C) | neutrons in the nucleus. |
| | D) | particles in the nucleus. |
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18 | |
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has |
| | A) | 9 neutrons. |
| | B) | 20 protons. |
| | C) | 11 neutrons. |
| | D) | 20 neutrons. |
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19 | |
Select the correct statement about the elements in the periodic table. Each |
| | A) | family begins with a single electron in a new outer energy level. |
| | B) | period has elements with similar properties. |
| | C) | period ends with the filling of an orbital in an outer energy level. |
| | D) | family has atoms with equal number of filled energy levels. |
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20 | |
The chemical properties of an element are determined by |
| | A) | the period to which it belongs. |
| | B) | number of filled energy levels. |
| | C) | number of electrons in its outer energy levels. |
| | D) | the total number of electrons. |
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21 | |
An element in the family VIA has |
| | A) | six electrons in its atom. |
| | B) | six occupied energy levels in its atom. |
| | C) | six electrons in its outer energy level. |
| | D) | five other elements in its family. |
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22 | |
Select the correct statement about elements in the periodic table. |
| | A) | Members of the A-group family are called transition elements. |
| | B) | Members of the B-group family are called representative elements. |
| | C) | Alkali metals are members of the group I |
| | D) | Alkaline earth metals are members of the group I |
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23 | |
Select the incorrect statement about halogens. |
| | A) | Halogens are nonmetals. |
| | B) | Halogens react with metals to form salts. |
| | C) | Halogens lie in group VII |
| | D) | Iodine is not a halogen. |
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24 | |
Which of the following is indicated by the number of dots in the electron dot notation. The number of electrons |
| | A) | in the atom. |
| | B) | in the outer energy level. |
| | C) | missing from the outer energy level. |
| | D) | in the inner energy levels. |
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25 | |
Select the term used to describe an atom that has acquired an unbalanced electron charge. |
| | A) | noble |
| | B) | semiconductor |
| | C) | allotropic |
| | D) | ion |
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