Chemistry 6.0
Electrons
Name_______________________________
The Periodic Law
1. Fill in the blank with the appropriate answer:
a) ______
Period 4, group 6 element
b) ______
Period 6 alkali metal
c) ______
period 3 metalloid
d) ______
A gas that typically forms ions with a charge of −2
e) ______
period 5 halogen
f) ______
the family of elements that form diatomics
g) ______
group 16, period 5
h) ______
used in light bulb filaments, this element has similar properties to molybdenum
i) ______
a metalloid with 5 valence electrons with a tendency to gain electrons.
j) ______
an unreactive period 4 element
k) ______
The transition metal with the lowest atomic number
l) ______
a period 2 metal that forms oxides of the general formula M2O
m) ______
the family of nonmetals that has all three states of matter represented
n) ______
the family of elements that do not typically form ions
o) ______
the family of elements that react with O2 in a 2 to 1 mole ratio
p) ______
the metal with the smallest atomic mass
q) ______
the series of elements that contains mendelevium
r) ______
the group number with seven valence electrons
s) ______
the family name of elements that form +1 ions
t) ______
group 13 metalloid
2. Write balanced equations for the reactions of each of the first three alkali metals with water. What
do these elements have in common that result in these similar reactions?
2
3. Write balanced equations for the electrolytic decomposition of the oxides of the first three alkaline
earth metals. What do these elements have in common that result in these similar reactions?
Wave – Particle Duality
Questions 4 – 8 refer to the electromagnetic wave pictured above.
4. What is the wavelength in meters? _____________
5. Given that 1.5x109 wave cycles pass a point in 1.0 microsecond, what is the frequency of the wave
in Hz?
6. In what part of the electromagnetic spectrum does this wave fall?
7. What is the velocity of this wave?
8. Sketch a wave over the wave above that has a higher frequency but a smaller amplitude.
9. If you make a wave of wavelength 2.5 m with a rope, what must be done in order to decrease the
wavelength to 1.25 m?
10. Indicate what determines or controls the following properties of a wave:
a. Frequency
_____________________
b. Speed
_____________________
c. Amplitude
_____________________
d. Wavelength
_____________________
3
11. Which has the greater:
a.
energy:
UV or IR
b.
frequency:
Red or Yellow
c.
wavelength:
Microwaves or Radio waves
12. The speed of light is _________________________ meters per second.
13. All waves can be described in terms of their amplitude, wavelength and ____________________.
14. The ___________________ of a wave is the number of complete waves passing a fixed point in a
given time.
15. The __________________________ __________________ is the range of wave frequencies from
radio waves to gamma waves.
16. The wavelength of microwave radiation is _______________ than the wavelength of visible light.
17. The color of visible light that has the longest wavelength is __________________.
18. A heat lamp produces _____________________ radiation.
19. A wave with a high frequency has a _______________ wavelength.
20. The brightness of light depends on the _____________________ of the light wave.
21. Microwaves are about one ________________________ long.
22. X-rays have ___________ wavelengths, ____________ frequency and ___________ energy.
23. Visible light is measured from ________nm (violet) to ________nm (red.)
24. If I lower the amplitude of a red wave, it becomes ____________ bright.
25. If I shorten the wavelength of a red wave it becomes _____________ light.
26. The relationship between frequency () and wavelength () is __________________ proportional.
27. Calculate and determine the type of EMR for:
a. the wavelength if the frequency is 1.20x1011 Hz.
b. the frequency if the wavelength is 3.4x10−9 m
c. the frequency when the wavelength is 490 nm.
d. the frequency when the wavelength is 26 nm.
4
28. How does the particle theory explain the photoelectric effect while the wave theory does not?
29. Calculate and determine the type of EMR:
15
a. the energy of a photon with a frequency of 8.77x10 s−1
b. the frequency of a photon with an energy of 1.88x10−25 J.
c. the energy of a photon if the wavelength is 2.99x10−5 m
d. the wavelength a photon with a energy of 4.85x10−19 J.
30. The minimum energy needed to remove an electron from potassium metal is 3.7 x 10−19 J. Will
photons of frequencies 4.3 x 1014 s−1 (red light) and 7.5 x 1014 s−1 (blue light) trigger the
photoelectric effect?
31. A sodium-vapor street lamp emits bright yellow light at a wavelength 589 nm. How much energy
is emitted per mole of sodium atoms?
5
32. A diode laser emits photons at a wavelength of 987 nm. How many photons would be required for
the total energy output of the laser to be 0.52 J?
33. The light reaching us from distant stars is extremely dim. Consequently, astronomers must use
instruments capable of detecting a small number of photons. An infrared photon detector
registered a signal at 1250 nm from Alpha Centauri with a total energy of 1.20 x 10−16 J. How
many photons were detected?
34. When minerals absorb “black light” from a mercury lamp, they emit visible light of a longer
wavelength, converting the remaining energy into heat.
a. How much energy per mole is converted to heat by a mineral that absorbs ultra violet light
at 366 nm and emits green light at 545 nm?
b. Assuming a complete transfer of the heat energy determined above, how many grams of
ice can be melted at its melting point?
35. Determine the minimum wavelength of a photon that possesses enough energy to break the bond
in a molecule of Cl2.
6
36. In the stratosphere, about 50 km above the earth’s surface, a thin layer of ozone, O3, is formed in a
two-step process:
Step 1
O2 → O + O circle one: endothermic or exothermic?
Step 2
O2 + O → O3 circle one: endothermic or exothermic?
The interactions of molecules and light in the ozone layer result in a delicate balance that holds
ozone concentration relatively constant. Photons with wavelengths in the 180- to 240- nm range
break apart O2 molecules. Photons with wavelengths in the 200- to 340-nm range break apart O3
molecules. Will 5.54 x 1020 photons with a total energy of 355 J be able to break the bonds in
oxygen or ozone?
37. An 18.36 g sample of hydrogen cyanide gas (C = 1.328 J/g•°C) is at STP in a 5.00 L expandable
container. When 1.609 x 1021 photons of light with a wavelength of 945Å are added to the gas, the
pressure of the gas changes to 1168 torr. What is the new volume of the gas after the addition of
the photons?
38. Hydrogen peroxide decomposes when exposed to sunlight according to the following equation: .
2H2O2 + 299 kJ → 2H2O + O2
a. Calculate the frequency of a photon that possesses the minimum amount of energy
required to decompose a single hydrogen peroxide molecule.
b. How many photons with a wavelength of 425 nm would be required to produce 1.68 g of
water?
c. If 3.99 x 1024 photons with a wavelength of 7.31 x 10−7 m is applied to a sample of
hydrogen peroxide, what volume of oxygen at 84.3 kPa and 25°C will be produced?
7
The Bohr Model of the Atom
39. When an electron in an atom falls from the fifth to the second energy level, 4.58 x 10−19 J of
energy is released.
a. What is the frequency of the EMR that is emitted?
b. What is the wavelength of the EMR in meters?
c. What is the wavelength in nanometers?
d. What type of radiation is this?
40. When an electron in a hydrogen atom falls from the fourth to the first energy level, a photon with a
wavelength of 973 Å is emitted.
a. What is the frequency of this radiation?
b. What is the Energy in Joules per photon?
c. What is the Energy in Joules per mole?
d. What part of the spectrum is this radiation?
8
n
Energy (J)
1
−2.18E-18
2
−5.45E-19
3
−2.42E-19
4
−1.36E-19
5
−8.72E-20
6
−6.06E-20
41. Given the allowable energy states (above) for electrons in a hydrogen atom, determine the
wavelength in meters and nanometers for the photons involved in the indicated electron
transitions. In each case specify the type of EMR and whether the photon is emitted or
absorbed.
a. n=1 to n=3
b. n=5 to n=4
c. n=3 to n=2
42. In terms of electron transitions, what do all emitted photons that fall in the visible spectrum have
in common? In the U.V spectrum? In the I.R. spectrum?
The Quantum Mechanical Model
43. Why does the Bohr model of the atom work well with the hydrogen atom, but not with atoms of
other elements?
9
44. Explain how the contributions of DeBroglie and Heisenberg discredited the Bohr model and led to
the quantum mechanical model.
45. The electron cloud is least dense where the probability of finding an electron is_______________.
46. The first principal energy level of the hydrogen atoms contains only a(n)__________ orbital.
47. All p orbitals are shaped like _______________________.
48. The 3s orbital differs from the 2s in that it is ________________________.
49. The number of sublevels in each principal energy level equals the ____________________
50. Which of the sublevels can be found in the fourth energy level of an atom? _______________
51. Complete the following charts:
Sublevel
Number of orbitals
Maximum number of electrons
in each sublevel
s
p
d
f
Energy
Level
Sublevels
available
Number of
orbitals in
each sublevel
Total Number
of electrons in
each sublevel
Maximum number
of electrons in the
energy level
1
s
s
p
1
1
3
2
2
6
2
2
8
3
4
52. What is the maximum number of electrons that can occupy the sixth energy level?
53. How many orbitals would make up the g sublevel?
54. What is the maximum number of electrons that could occupy the h sublevel?
10
55. Write the complete electron configuration and orbital notation for the following elements.
a. Phosphorus
b. Sodium
c. Oxygen
d. Argon
e. Calcium
56. Identify the element that has the following electron configuration:
a. 1s22s22p3
b. 1s22s22p63s23p64s23d104p5
c. 1s22s22p63s23p2
d. 1s22s22p6
e. 1s22s22p63s23p64s23d10
f. 1s22s22p63s23p64s2
g. 1s22s22p63s23p64s23d104p65s24d105p66s24f145d6
57. Write the complete electron configuration for the following:
a. Cadmium
b. Selenium
c. Cesium
d. Bismuth
e. Radon
f. Seaborgium
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58. Write the noble gas configuration for:
a. barium
b. mercury
c. tellurium
d. thallium
e. tungsten
f. arsenic
59. Look at the following ground state orbital box diagrams, if there is a mistake, correct it.
a.
2s
2p
y
x
sodium
z
2s
2s
3p
z
y
x
2p
y
x
z
3s
3p
z
y
x
z
         
1s
2s
x
e. gallium
  
3s
y
z
       
1s
potassium

2p
x
c. phosphorus
y
x
    
1s
d.
z
    
1s
b.
y
x
nitrogen
2p
y
3s
z
x
3p
y
4s
3d
z
              
1s
2s
2p
3s
3p
4s
3d
12
60. Draw the orbital notations (beyond the noble gas core) for the following:
a. cobalt
b. polonium
c. gallium
d. fluorine
e. iron
f. iodine
61. What is the total number of electrons that will be in p orbitals in 8.31 moles of ground state zinc
atoms?
62. What is the total number of electrons that will be in s orbitals in 2.336 mg of ground state cesium
atoms?
13
63. For each of the following electron transitions, indicate whether the electron would need to absorb
or emit energy.
a. 3s to 3p
_________________ c. 3d to 4s _________________
b. 5s to 4d
_________________
d. 3p to 2s _________________
64. For each of the following atoms state whether the electron configuration is written in the ground
state or the excited state.
a. oxygen: 1s2 2s2 2p3 3s1
_________________
b. potassium: 1s2 2s2 2p6 3s2 3p6 3d1
_________________
c. chlorine: 1s2 2s2 2p6 3s2 3p5
_________________
d. krypton: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 5s1
_________________
65. It has been found that substances with one or more unpaired electrons are magnetic. The more
unpaired electrons, the more magnetic the substance. For each of the following pairs of elements
draw the orbital notation beyond the noble gas core and predict which is more magnetic.
a. sodium and magnesium
b.
aluminum and phosphorous
66. Write the shortened configuration and orbital notation for:
a. Silver
b. Molybdenum
c. Gold
14
Review
67. Match the scientists with the listed accomplishments.
a.
b.
c.
d.
e.
Dimitri Mendeleev
Henry Moseley
J.J. Thompson
Niels Bohr
Max Planck
f.
g.
h.
i.
Albert Einstein
Louis De Broglie
Werner Heisenberg
Erwin Schrodinger
_____proposed the plum pudding model for the atom
_____developed the concept of matter waves
_____postulated that electron arrangement is a matter of probability
_____determined that the energy of a photon is related to its frequency
_____introduced the concept of atomic numbers to the periodic table
_____suggested that light is composed of both particles and waves
_____grouped elements together with similar properties
_____proposed that electrons orbit the nucleus and have an allowable amount of energy
_____stated that the position and momentum of an electron can’t be known simultaneously
68. List 3 elements that have similar properties to magnesium
69. Identify the element
a. Group 6, period 5
b. Group 17, period 4
c. Period 5 Alkaline earth metal
d. [Ar] 4s2 3d3
70. Which has the:
a. longer wavelength?
green or
b. higher frequency?
Gamma rays or
c. greater speed?
UV
or
yellow
IR
microwaves
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71. Calculate and determine the type of EMR:
a. the wavelength when the frequency is 2.5x106 Hz.
b. the energy when the wavelength is 3.59x109nm.
72. What distance, in kilometers, does electromagnetic radiation travel in 6.54 s?
73. Calculate the energy of 1 mole of photons with a frequency of 5.72 x 1013 s−1.
74. Calculate the frequency required of an absorbed photon if it causes the electron in a hydrogen
atom to jump from the ground state (n=1) to n=3.
75. Use the following information regarding the given reaction to determine how many photons of a
light source with a wavelength of 185 nm are needed to supply the necessary activation energy to
initiate the reaction. The enthalpy of the products of the reaction are 840 kJ and the activated
complex possesses 2780 kJ.
16
76. If the energy of 1.26 x 10 photons with a wavelength of 692 nm is transferred to 13.6 g of water
at 27.0°C, what will the temperature of the water become?
21
77. Write the complete configuration for each of the following:
a. Ru
b. Pb
c. Hf
78. Write the noble gas configuration for each of the following:
a. Ca
b. Te
c. At
d. Mo
17
79. Draw the orbital notation (beyond the noble gas core) for the elements in the previous question.
a.
b.
c.
d.
80. What is the total number of electrons that will be in f orbitals in 0.8943 moles of ground state
bismuth atoms?
Cumulative Review Questions
81. How many significant figures are in each of these measurements?
a. 143 g
________
d. 1.072 km
________
b. 0.074 cm
________
e. 10800 cal
________
c. 8.750 x 10−2 ng
________
f. 5.00 dm3
________
82. Convert 27.37 miles per hour to centimeters per day.
83. Given that the density of sulfur is 2.1 g/cm3, what volume would 19.45 grams of sulfur occupy?
18
84. Classify the following as an element (E), compound (C), Solution (S), or Heterogeneous Mixture
(HM).
a. spring water
_______
d. carbon dioxide
_______
b. table sugar
_______
e. 18 karat gold
_______
c. molten sodium
_______
f. gasoline
_______
85. In which state of matter do the following exist at room temperature and atmospheric pressure?
a. diamond
_____________
d. mercury
_____________
b. oxygen
_____________
e. glass
_____________
c. cooking oil
_____________
f. neon
_____________
86. Complete the following table.
Standard
Atomic
Mass Number
Isotopic
Number
Notation
Number of
Protons
34
83
38
Number of
Neutrons
Number of
Electrons
18
18
Sr 2
92
146
87. The 4 isotopes of lead are shown below, with their respective nuclear compositions and relative
abundances. Use this data to calculate the atomic mass of lead.
82 p+
122 n0
82 p+
124 n0
82 p+
125 n0
82 p+
126 n0
1.37%
26.26%
20.82%
51.55%
88. Tell how alpha, beta, and gamma radiation are distinguished on the basis of the following.
mass
charge
penetrating power
alpha
beta
gamma
19
89. Write nuclear equations for each of the following.
a. alpha decay of bismuth-214
b. beta decay of silicon-27
c. alpha bombardment of aluminum-27 to produce silcon-30 and…
d. electron capture by nitrogen-15
90. The half-life of thorium-234 is 25 days. A 5.00 gram sample of thorium undergoes decay for 1.23
years. What mass of sample remains?
91. Write balanced equations for the following.
a. barium carbonate is heated
b. potassium metal is heated in the presence of sodium oxide
c. C8H16 is combusted
d. Solutions of rubidium hydroxide and hypochlorous acid are mixed
92. Magnesium nitride will react with water to produce magnesium hydroxide and ammonia gas. If
you initiate the reaction using 58.1 g of magnesium nitride and 20.4 g of water, how many grams
of magnesium hydroxide will be formed? How many grams of excess reactant will remain?