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MW
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Student Name _______________________________ _______________
Lab Section (circle one)
Chapter 3 Homework Problems
CHEM 1A
1. Given the following valence level orbital notations for neutral ground state atoms:
⥮ ↿↿
⥮ ⥮↿⇂ ↿
⥮
3s
2s
5s
3p
2p
⥮ ⥮↿ ↿
5p
3s
3p
(a) identify each element (insert element symbol in the spaces above)
(b) rank the four elements in order of increasing size
____ < ____ < ____ < ____
(c) rank them in order of increasing ionization energy
____ < ____ < ____ < ____
2. Label each atom on the reactant side as a metal or a non-metal. Label each ion on the product side
as a cation or an anion?
green
blue
green
blue
3. Answer the following question about ionization energies (IE)
(a) Why do successive IEs of a given element always increase (IE1 < IE2 < IE3 …)?
(b) When the difference between successive IEs of a given element is exceptionally large (for
example, between IE1 and IE2 of K), what do we learn about its electron configuration?
(c) The bars to the right represent the relative magnitudes of the
first five ionization energies of an atom:
Identify the element and write its complete electron
configuration, assuming that it comes from Period 2.
CHEM 1A – Chapter 3 – Page 1 of 3
4. Determine the numbers of protons and electrons in: Ti4+, S2–, Ca2+, Sc3+. Order them according to
their expected sizes, and explain your answer.
Ti4+ S2–
Ca2+
p
e–
Sc3+
____ < ____ < ____ < ____
5. What are the ground-state noble gas electron configurations of the following cations?
(a) La3+
(b) Ag+
(c) Sn2+
6. Considering periodic trends and whether full-shell electron configurations are achieved or disrupted:
(a) Which has the smaller fourth ionization energy, Sn or Sb?
(b) Which has the larger third ionization energy, Mg or Al?
(c) Which element has the largest second ionization energy?
7. Which of the following alkali metal
halides has the largest lattice energy?
Which has the smallest lattice energy?
Explain.
8. Order the following compounds according to their expected lattice energies: AlBr3, MgBr2, LiBr,
CaO.
_______ < _______ < _______ < _______
CHEM 1A – Chapter 3 – Page 2 of 3
9. Consider the electronic structure of the element bismuth.
(a) The first ionization energy of bismuth is Ei1 = + 703 kJ/mol. What is the longest possible
wavelength (in m) of light that could ionize an atom of bismuth?
Hints: convert kJ/mol to J/e– ; Ephoton is always positive, so you don’t need to change the
sign of the energy absorbed by the electron (also positive in sign)
(b) Give the valence level orbital notation of a neutral Bi atom:
(c) What are four quantum numbers of the electron removed when Bi is ionized to Bi+?
(d) Do you expect element 115 to have an ionization energy greater than, equal to, or less than
that of bismuth? Explain.
10. Write formulas for the following compounds:
(a)
(b)
(c)
(d)
calcium acetate
iron (II) cyanide
sodium dichromate
chromium (III) sulfate
11. Name each of the following compounds:
(a)
(b)
(c)
(d)
KMnO4
Co(NO2)2
Mn(HCO3)2
ZnCrO4
12. Tellurium, a group VIA element, forms the oxyanions TeO42– and TeO32–.
What are the names of these ions? To what other group VIA oxoanions are they analogous?
CHEM 1A – Chapter 3 – Page 3 of 3