SCH4U
Review of Structure and Properties.
1. Consider the ion, Sr2+.
a) Write its electronic configuration (no short form).
b) Give two other ions that have exactly the same electronic configuration, i.e. are isoelectronic with Sr 2+.
c) Which noble gas atom has the same configuration?
d) Write four acceptable quantum numbers for an electron in the valence shell of an atom of strontium.
2. Which of the following electronic notations represents an excited atom?
a. 1s2 2s2p6 3s2p6d2
excited
not excited
b. 1s2 2s2p6 3s2p6d10 4s1
excited
not excited
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c. [Ar]
4s
excited
not excited
3. Draw a Lewis structure, give the steric number of, state the bond angles, and name the structure of:
a. PI3
b. XeF2
c. HSO34. Which of the following has a lower boiling point, and why? CO2 or CS2 ?
5. What hybridization would you expect to be used to explain the structure and geometry of
a. SF4
________________
b. CS2
________________
6. For each of the following draw the Lewis structure and an arrow to indicate the direction of a dipole, if there
is one. If there is no dipole then say so.
a)
CS2
b) CF2H2
c)
NH3
7. Which of the following would be expected to have the higher melting point? Explain.
a. BaS or CaO
b. MgO or AlN
8. First ionization energy is the energy required to remove an electron from a gaseous atom. Second
ionization energy is the energy required to remove an electron from a gaseous +1 cation. Third ionization
energy is the energy required to remove an electron from a 2+ gaseous cation. The first ionization energy
of element X is 737.7 V, the second ionization energy is 1450.6 V, and the third ionization energy is 7732.6
V. What family would you expect element X to belong to? Explain.
9. Sketch a diagram to show the ground state configuration, the hypothetical promoted state and the
hybridization that occurs on phosphorus when it forms PH3.
10. Fill in the missing values in the chart below. Where there may be more than one “correct value”, only give
one answer.
n
l
ml
2
3
1
0
-2
name (e.g. 7f)
4p
6s
11. The electron configurations given below represent atoms that may be in excited states.
a. Identify the elements
b. Indicate whether they are in an excited state or not and write the ground state configuration.
Electron Configuration
Element
? Excited yes/no
Ground State Configuration
1s22s22p63s23p1
1s22s22p6 3s13d4
1s22s22p63s23p63d2
12. Why is it not possible to ever have more than 8 valence electrons in any given atom?
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SCH4U
Review of Structure and Properties.
13. Complete the following chart. If no hybridization occurs, indicate this with a diagonal line through the
corresponding box.
Compound
Steric number of atom indicated
Hybrid Orbital type formed
C3H8
C
C
CO2
C
C
SH6
S
S
14. Using your knowledge of hybrid orbitals, explain why the family V compound PCl5 forms, but NCl5 does
not.
15. Write the ground state electronic configuration of an atom of selenium. (no short form)
a)
b)
c)
d)
How many unpaired electrons does it have?
In which block of the periodic table is it found?
How many valence electrons does it have?
Write four acceptable quantum numbers for an electron in the valence shell of this atom.
16. Complete the following table for the four types of crystals studied.
Solid Type
Ionic
Covalent
Network
Molecular
Metallic
Particles
Force/Bond
Properties
(list two)
17. Diamond and graphite are both composed entirely of carbon. Explain, with reference to their bonding, why
the physical properties of these substances are so different.
18. The given/accepted electron configuration for Cm, curium, is [Rn]5f87s2.
a. What would you expect the electron configuration for Cm to be if the Aufbau rules were exactly followed?
b. Explain why it is not too surprising that Cm is actually [Rn]5f76d17s2.
19. Gendronium, Gn, is a fictitious element. It forms the stable compound GnF3, in which all the F-Gn-F bond
angles are 90°. Suggest a family of the periodic table to which gendronium could belong and explain your
reasoning.
20. Describe one physical property of covalent network solids and explain it in terms of the bonding model of
these compounds.
21. An engineer has found a metal which satisfactorily illustrates the photoelectric effect. She wishes to create
more voltage (more energy per electron). How should she adjust her setup so that more voltage is produced?
Explain.
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