Chemistry Test

Unit Three

Atomic Theory

Choose the best answer to each of the following questions.

  1. Which of the following ideas about matter did Aristotle have?
    (A) Specific substances always contain elements in the same ratio by
          mass.
    (B) Matter is continuous and can be continually broken down.
    (C) There is a different type of atom for each type of material.
    (D) Matter is made up of atoms.

  2. Which of the following is an example of the law of multiple proportions?
    (A) CO2 and N2O
    (B) N2O and N2O5
    (C) N2O5 and CO2
    (D) CO2 and H2O

  3. Which of the following statements is not part of Dalton’s atomic theory?
    (A) Atoms are made up of protons and electrons.
       (B) Atoms unite in definite ratios to form compounds.
       (C) All matter is made up of atoms.
       (D) A chemical reaction is the rearrangement of atoms.

  4.  Which of the following statement made by Dalton in his atomic
       theory is incorrect?
       (A) All matter is composed of atoms.
       (B) All atoms of the same element are alike.
       (C) All atoms of different elements are different.
       (D) A chemical reaction is were atoms get rearranged.

   5. The electric charge and mass number of a neutron are, respectively,
       ____________
       (A) 0 and 1
       (B) +1 and 0
       (C) +1 and 1
       (D) –1 and 1

   6. Two isotopes of an element have different ___________
       (A) numbers of electrons.
       (B) Numbers of protons.
       (C) Atomic numbers.
       (D) Mass numbers.

   7. In atomic notation, the atomic number is given what symbol?
       (A) A
       (B) N
       (C) Z
       (D) X

   8. The Millikan Oil Drop Experiment demonstrated that
       _______________________
      (A) The atom was mostly empty space.
      (B) The size of the charge on the electron.
      (C) Protons are found inside the nucleus of an atom.
      (D) The electron orbits the nucleus of an atom.

   9. The set of wavelengths absorbed or emitted by a substance is its
       _________
       (A) ground state.
       (B) mass number.
       (C) quantum number.
       (D) Spectrum.

  10. What is the frequency of ultraviolet light that has a wavelength of
       2.52 x 10-7 m? (The speed of light is 3.00 x 108 m/s)
       (A) 7.59 x 1014 Hz
       (B) 8.40 x 10-16 Hz
        (c) 2.56 x 1015 Hz
       (D) 1.19 x 1015 Hz

  11. Atomic mass is a relative scale based upon which of the following?
       (A) carbon-12
       (B) nitrogen-12
       (C) oxygen-16
       (D) hydrogen-1

  12. Which subatomic particles are of approximate equal mass?
        (A) Protons and electrons.
        (B) Neutrons and protons
        (C) Neutrons, protons and electrons.
        (D)Neutrons and electrons.

  13. The mass spectrometer can be used to ____________
       (A) Determine electron speed.
       (B) Determine the density of an atom.
       (C) Separate protons.
       (D) Separate isotopes.

  14. Which of the following is an example of isotopes?
        (A) Carbon-14, carbon-13, carbon-12
        (B) Hydrogen-1, helium-3
        (C) Nitrogen-14, nitrogen-14
        (D) Lithium-3, sodium-21

 

Free Response

You must show all work to receive full credit.

     

  1. Find the number of protons, electrons and neutrons in a neutral atom of chlorine-35, atomic number 17.

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  2. Calculate the wavelength of green light that has a frequency of 8.37 x 1014 Hz. The speed of light is 3.00 x 108 m/s

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  3. Calculate the energy of a green photon that has the wavelength in question number 2. (h = 6.64 x 10-34 J Hz; c = 3.00 x 108 m/s)

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  4. Describe the contributions made toward our understanding of the atom from John Dalton, J.J. Thomson, Ernst Rutherford, and Niels Bohr.

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  5. "Atomic spectra are considered the ‘fingerprints’ of atoms." Explain this statement

 

 

 

 

 

 

6. What is the difference between and absorption spectra and an emission
    spectra?