Atomic Spectra Worksheet - DOC by knt16405


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									Chemistry Chapter 5
Complete the worksheet while viewing the power point. Use your textbook to answer remaining questions after the
power point. Some information repeats itself. Consider this the important concepts in the chapter.

Name of chapter:

5.1 Timeline (p. 128-129)

     1803                                       1904

                               1897                                            1911

1923                           1923                                                   1932

     1913                                                   1926

Quantum mechanical model

Atomic orbitals

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Electromagnetic radiation

Atomic emission spectrum
ground state


5.1 The Development of Atomic Models
1. Rutherford’s atomic model could not explain
   a. why _________________________________give off characteristic colors when heated
   b. why objects ___________________________ first glow dull red, then yellow, then white.
   c. his model could not explain ____________________________________.

The Bohr Model
2. Bohr proposed that an electron is found only in specific circular paths, or _________, around
   the nucleus.
3. Each possible electron orbit in Bohr’s model has a fixed energy called ____________.
4. A quantum of energy is the amount of energy required to move an electron

The Quantum Mechanical Model
5. Erwin Shrodinger used math to propose the ___________________________ model.
6. The quantum mechanical model determines the allowed energies an electron can have and
how likely it is ______________________________________________________

Atomic Orbitals
7. An _______________________ is often thought of as a region of space in which there is a
high probability of finding an electron. The s orbitals are _____________ shaped, and p orbitals
are __________________ shaped.

Table 5.1
              Summary of Principal Energy Levels, Sublevels, and Orbitals
Principal Energy Level Number of sublevels                Type of sublevel
          n=1                                 1s (1 orbital)
          n=2                     2

         n=3                       3

         n=4                                     4s (1 orbital), 4p (3 orbitals), 4d (5
                                                 orbitals), 4f (7 orbitals)

5.2 Electron Configurations
8. The ways in which electrons are arranged in various orbitals around the nuclei of atoms are
called ________________________.
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9. Aufbau principle: electrons occupy the orbitals of _________ energy first.
Pauli exclusion principle: an atomic orbital may describe at most ____________. To occupy the
same orbital, two electrons must have ______________; that is, the electron spins must be
Hund’s rule: electrons occupy orbitals of the ______________ in a way that makes the number
of electrons with the _____________ direction as large as possible.
Some actual electron configurations differ from those assigned using the aufbau principle
because __________sublevels are not as stable as _________ sublevels, but they are more stable
than other configurations.
Exceptions to the aufbau principle are due to ___________________________________ in
orbitals with very similar energies.
                       Electron Configurations for Some Selected Elements
                                    Orbital filling
Element     1s        2s       2 px          2 py     2 pz   3s     Electron
            ↑                                                       1s1
   He       ↑↓
            ↑↓        ↑                                             1s2 2s1
    C       ↑↓        ↑↓       ↑             ↑
            ↑↓        ↑↓       ↑             ↑        ↑             1s2 2s2 2p3
    O       ↑↓        ↑↓       ↑↓            ↑        ↑
            ↑↓        ↑↓       ↑↓            ↑↓       ↑             1s 2 2s2 2p5
   Ne       ↑↓        ↑↓       ↑↓            ↑↓       ↑↓
            ↑↓        ↑↓       ↑↓            ↑↓       ↑↓     ↑      1s2 2s2 2p6 3s1

5.3 Physics and the Quantum Mechanical Model—Light
10. The __________________ of a wave is the wave’s height from zero to the crest. The
______________________, represented by _________, is the distance between the crests. The
_________________, represented by _______, is the number of wave cycles to pass a given
point per unit of time. The SI unit for cycles per second is the ___________. The speed of light
is _________________. Draw a picture of a wave and label the parts.

11. ___________________________________ include radio waves, microwaves, infrared
waves, visible light, ultraviolet waves, X-rays, and gamma rays.
12. When sunlight passes through a prism, the different frequencies separate into a
______________ of colors. The lowest frequency and longest wavelength is _____________.
The other colors in order are _____________________________________________________.

Atomic Spectra and Explanation of Atomic Spectra
13. When atoms absorb energy, __________ move into higher energy levels. These electrons
then lose energy by ________________ when they return to lower energy levels.
14. The frequencies of light emitted by an element separate into discrete lines to give the
_____________________ of the element.
15. When the electron has its lowest possible energy, the atom is in its _______________.
16. Excitation of the electron by absorbing energy raises the atom from the ground state to an
 17. A quantum of energy in the form of light (photon) is emitted when the electron drops back to
a ___________________.
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18. The light emitted by an electron moving from a higher to a lower energy level has a
frequency __________ proportional to the energy change of the electron.

Quantum Mechanics
19. Einstein proposed that light could be described as quanta of energy called ______________.
The quanta behave as if they were ____________________, resulting in a dual wave-particle
20. In 1924, De Broglie developed an equation that predicts that all moving objects have
___________________ behavior.
21. The older theory of classical mechanics, adequately describes _____________________
_____________________________________, while the newer theory of quantum mechanics
describes ___________________________________________________________________.
22. The ___________________ uncertainty principle states that it is impossible to know exactly
both the velocity and the position of a particle at the same time. The very act of measuring the
position of an electron changes it velocity, and makes its velocity uncertain.

Review…5.2 Electron Configurations (pages 133–135)
1. The ways in which electrons are arranged around the nuclei of atoms are
called ___________________________________________ .
2. In the shorthand method for writing an electron configuration, what does a
superscript stand for? What do the sum of the superscripts equal?
5.3 Light (pages 138–140)
1. Match each term describing waves to its definition.
_______ amplitude                      a. the distance between two crests
_______ wavelength                     b. the wave’s height from the origin to the crest
_______ frequency c. the number of wave cycles to pass a given point per unit of time
Atomic Spectra (page 141)
4. What happens when an electric current is passed through the gas or vapor of
an element?
5. Is the following sentence true or false? Explain. The emission spectrum of an element
can be the same as the emission spectrum of another element.
An Explanation of Atomic Spectra (pages 142–143)
6. What is the lowest possible energy of an electron called?
7. Only electrons moving from ______________________ to
______________________ energy levels lose energy and emit light.
Ch. 4 review question
 _______________ discovered the electron in 1897. He sealed gases in a tube and put electricity
through the tube. The result was a glowing beam, or ________________ ray. By using a
magnet, he showed that there were tiny _______________ charged particles moving at high
speeds (corpuscles or electrons). He found that the charge-to-mass ratio of electrons did not
depend on the kind of gas used or type of metal plates. Thus, electrons must be part of the atoms
of all elements.

Chemistry—Ch. 5 textbook problems p. 149-151 (22-26, 30, 34-35, 40, 43, 61-65, 68)

22. What was inadequate about Rutherford’s model of the atom? Which subatomic particles did
Thomson include in the plum-pudding model of the atom?

23. What did Bohr assume about the motion of electrons?
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24. Describe Rutherford’s model of the atom and compare it with the model proposed by his
student Niels Bohr.

25. What is the significance of the boundary of an electron cloud?

26. What is an atomic orbital?

30. How many electrons are in the highest occupied energy level of these atoms?
       a) barium                              b) sodium
       c) aluminum                            d) oxygen
34. Give electron configurations for atoms of these elements:
       a) Na                                  d) Ne
       b) S                                   e) K
       c) Mg
35. Which of these orbital designations are invalid?
       a) 4s                                  c) 3f
       b) 2d                                  d) 3d

40. List the colors of the visible spectrum in order of increasing wavelength.

43. Explain the difference between the energy lost or gained by an atom according to the laws of
classical physics and according to the quantum model of an atom.

61. Pieces of energy are known as
       a) isotopes                            b) particles
       c) quanta                              d) line spectra
62. The lowest sublevel in each principal energy level is represented b the symbol
       a) f                                   b) p
       c) s                                   d) d
63. Which electron transition results in the emission of energy?
       a) 3p to 3s                            b) 3p to 4p
       c) 2s to 2p                            d) 1s to 2s
64. Which is the ground state configuration of a magnesium atom?
       a) 1s22s22p63s2                        b) 1s22s22p63s1
            2 2 2     6
       c) 1s 2s 3s 2p                         d) 1s22s22p43s2
65. Explain the difference between an orbit in the Bohr model and an orbital in the quantum
mechanical model of the atom.

68. Orbital diagrams for the ground states of two elements are shown below. Each diagram
shows something that is incorrect. Identify the error in each diagram and then draw the correct

     a. Nitrogen

     b. Magnesium

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