Chapter 7: Atomic Theory & Periodic Properties AP Questions
1984
22. 1s2 2s22p63s23p3
Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed
with magnesium, Mg, is
(A) MgX
(D) MgX3
(B) Mg2X
(E) Mg3X2
(C) MgX2
43. The elements in which of the following have most nearly the same atomic radius?
(A) Be, B, C, N
(D) C, P, Se, I
(B) Ne, Ar, Kr, Xe
(E) Cr, Mn, Fe, Co
(C) Mg, Ca, Sr, Ba
58. Which of the following represents the ground state electron configuration for the Mn3+ ion? (Atomic number
Mn = 25)
(A) 1s2 2s22p6 3s23p63d4
(D) 1s2 2s22p6 3s23p63d8 4s2
2
2
6
2
6
5
2
(B) 1s 2s 2p 3s 3p 3d 4s
(E) 1s2 2s22p6 3s23p63d3 4s1
2
2
6
2
6
2
2
(C) 1s 2s 2p 3s 3p 3d 4s
66. Ca, V, Co, Zn, As
Gaseous atoms of which of the elements above are paramagnetic?
(A) Ca and As only
(D) V, Co, and As only
(B) Zn and As only
(E) V, Co, and Zn only
(C) Ca, V, and Co only
1989 Use these answers for questions 1-3.
(A) O
(B) La
(C) Rb
(D) Mg
(E) N
1. What is the most electronegative element of the above?
2. Which element exhibits the greatest number of different oxidation states?
3. Which of the elements above has the smallest ionic radius for its most commonly found ion?
Use these answers for questions 4-7.
(A) 1s2 2s2 2p5 3s2 3p5
(B) 1s2 2s2 2p6 3s2 3p6
(C) 1s2 2s2 2p6 2d10 3s2 3p6
4. An impossible electronic configuration
(D) 1s2 2s2 2p6 3s2 3p6 3d5
(E) 1s2 2s2 2p6 3s2 3p6 3d3 4s2
5. The ground-state configuration for the atoms of a transition element
6. The ground-state configuration of a negative ion of a halogen
7. The ground-state configuration of a common ion of an alkaline earth element
1999
Questions 5-8 refer to atoms for which the occupied atomic orbitals are shown below.
5. Represents an atom that is chemically unreactive
6. Represents an atom in an excited state
7. Represents an atom that has four valence electrons
8. Represents an atom of a transition metal
Ionization Energies for element X (kJ mol-1)
First
Second
Third
Fourth
Fifth
580
1,815
2,740
11,600
14,800
37. The ionization energies for element X are listed in the table above. On the basis of the data, element X is
most likely to be
(A) Na
(B) Mg
(C) Al
(D) Si
(E) P
50. In the periodic table, as the atomic number increases from 11 to 17, what happens to the atomic radius?
(A) It remains constant.
(D) It decreases only.
(B) It increases only.
(E) It decreases, then increases.
(C) It increases, then decreases.
2002
Consider atoms of the following elements. Assume that the atoms are in the ground state.
(A) S
(B) Ca
(C) Ga
(D) Sb
(E) Br
1. The atom that contains exactly two unpaired electrons
2. The atom that contains only one electron in the highest occupied energy sublevel
17. In which of the following groups are the three species isoelectronic; i.e., have the same number of electrons?
(A) S2-, K+, Ca2+
(D) Mg2+, Ca2+, Sr2+
(B) Sc, Ti, V2+
(E) Cs, Ba2+, La3+
22(C) O , S , Cl
44. Which of the following properties generally decreases across the periodic table from sodium to chlorine?
(A) First ionization energy
(D) Maximum value of oxidation number
(B) Atomic mass
(E) Atomic radius
(C) Electronegativity
46. The effective nuclear charge experienced by the outermost electron of Na is different than the effective
nuclear charge experienced by the outermost electron of Ne. This difference best accounts for which of the
following?
(A) Na has a greater density at standard conditions than Ne.
(B) Na has a lower first ionization energy than Ne.
(C) Na has a higher melting point than Ne.
(D) Na has a higher neutron-to-proton ratio than Ne.
(E) Na has fewer naturally occurring isotopes than Ne.
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1994
Use principles of atomic structure and/or chemical bonding to answer each of the following.
(a) The radius of the Ca atom is 0.197 nanometer; the radius of the Ca2+ ion is 0.099 nanometer. Account for
this difference.
(b) The lattice energy of CaO(s) is -3,460 kilojoules per mole; the lattice energy
for K2O(s) is -2,240 kilojoules per mole. Account for this difference.
(c) Explain the difference between Ca and K in regard to
(i) their first ionization energies,
(ii) their second ionization energies.
(d) The first ionization energy of Mg is 738 kilojoules per mole and that of Al is
578 kilojoules per mole. Account for this difference.
K
Ca
Ionization Energy
(kJ/mol)
First
Second
419
3,050
590
1,140
2003 B (8 pts)
7. Account for the following observations using principles of atomic structure and/or chemical bonding. In
each part., your answer must include specific information about both substances.
(a) The Ca2+ and Cl- ions are isoelectronic, but their radii are not the same. Which ion has the larger radius?
Explain.
(b) Carbon and lead are in the same group of elements, but carbon is classified as a nonmetal and lead is
classified as a metal.
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2007
Ele m e n t
Ele m e n t
Ele m e n t
Ele m e n t
1
2
3
4
Fir st
Io n iza t io n
En e r gy
( k J m o l -1 )
1 ,2 5 1
496
738
1 ,0 0 0
Se co n d
Io n iza t io n
En e r gy
( k J m o l -1 )
2 ,3 0 0
4 ,5 6 0
1 ,4 5 0
2 ,2 5 0
Th ir d
Io n iza t io n
En e r gy
( k J m o l -1 )
3 ,8 2 0
6 ,9 1 0
7 ,7 3 0
3 ,3 6 0
6. The table above shows the first three ionization energies for atoms of four elements from the third period of
the periodic table. The elements are numbered randomly. Use the information in the table to answer the
following questions.
(a) Which element is most metallic in character? Explain your reasoning.
(b) Identify element 3. Explain your reasoning.
(c) Write the complete electron configuration for an atom of element 3.
(d) What is the expected oxidation state for the most common ion of element 2?
(e) What is the chemical symbol for element 2?
(f) A neutral atom of which of the four elements has the smallest radius?
2008
5. Using principles of atomic and molecular structure and the
information in the table below, answer the following questions about
atomic fluorine, oxygen, and xenon, as well as some of their compounds.
At o m
Fir st Io n iza t io n
En e r gy ( k J m o l -1 )
F
1 ,6 8 1 .0
(a) Write the equation for the ionization of atomic fluorine that requires
1,681.0 kJ mol-1.
O
1 ,3 1 3 .9
(b) Account for the fact that the first ionization energy of atomic fluorine
is greater than that of atomic oxygen. (You must discuss both atoms
Xe
?
in your response.)
(c) Predict whether the first ionization energy of atomic xenon is greater than, less than, or equal to the first
ionization energy of atomic fluorine. Justify your prediction.
(d) Xenon can react with oxygen and fluorine to form compounds such as XeO3 and XeF4. In the boxes
provided, draw the complete Lewis electron-dot diagram for each of the molecules represented below.
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