Exercises 265Roasting Heating an ore of an element in the presence of air.
Shielding effect Electrons in filled sets of sand p orbitals
between the nucleus and outer shell electrons shield the outer
shell electrons somewhat from the effect of protons in the
nucleus; also called screening effect.
Superoxide A compound containing the superoxide ion, O 2
(oxygen in the ^12 oxidation state).
Ternary acid An acid containing three elements: H, O, and (usu-
ally) another nonmetal.Exercises
Classification of the Elements
*01.Define and illustrate the following terms clearly and
concisely: (a) representative elements; (b) d-transition ele-
ments; (c) inner transition elements.
*02.Explain why Period 1 contains two elements and Period 2
contains eight elements.
*03.Explain why Period 4 contains 18 elements.
*04.The third shell (n3) has s, p,and dsubshells. Why does
Period 3 contain only eight elements?
*05.Account for the number of elements in Period 6.
0 *6.What would be the atomic number of the as-yet-
undiscovered alkaline earth element of Period 8?
*07.Identify the group, family, or other periodic table location
of each element with the outer electron configuration
(a) ns^2 np^4
(b) ns^2
(c) ns^2 (n1)d^0 ^2 (n2)f^1 ^14
*08.Repeat Exercise 7 for
(a) ns^2 np^6
(b) ns^1
(c) ns^2 (n1)d^1 ^10
(d) ns^2 np^1
*09.Write the outer electron configurations for the (a) alkaline
earth metals; (b) first column of d-transition metals; and
(c) halogens.
*10.Which of the elements in the following periodic table is
(are) (a) alkali metals; (b) an element with the outer con-
figuration of d^7 s^2 ; (c) lanthanides; (d) p-block representative
elements; (e) elements with partially filled f-subshells;
(f) halogens; (g) s-block representative elements;
(h) actinides; (i) d-transition elements; (j) noble gases?*11.Identify the elements and the part of the periodic table in
which the elements with the following configurations are
found.
(a) 1s^22 s^22 p^63 s^23 p^64 s^2
(b) [Kr] 4d^85 s^2
(c) [Xe] 4f^145 d^56 s^1
(d) [Xe] 4f^126 s^2
(e) [Kr] 4d^105 s^25 p^3
(f) [Kr] 4d^104 f^145 s^25 p^65 d^106 s^26 p^2
*12.Which of the following species are iso-electronic?
O^2 , F, Ne, Na, Mg^2 , Al^3
*13.Which of the following species are iso-electronic?
P^3 , S^2 , Cl, Ar, K, CaAtomic Radii
*14.What is meant by nuclear shielding? What effect does it
have on trends in atomic radii?
*15.Why do atomic radii decrease from left to right within a
period in the periodic table?
*16.Consider the elements in Group VIA. Even though it has
not been isolated or synthesized, what can be predicted
about the ionic radius of element number 116?
*17.Variations in the atomic radii of the transition elements are
not so pronounced as those of the representative elements.
Why?
*18.Arrange each of the following sets of atoms in order of
increasing atomic radii: (a) the alkaline earth elements;
(b) the noble gases; (c) the representative elements in the
third period; (d) N, Ba, B, Sr, and Sb.
*19.Arrange each of the following sets of atoms in order of
increasing atomic volume: (a) O, Mg, Al, Si; (b) O, S, Se,
Te; (c) Ca, Sr, Ga, AsIonization Energy
*20.Define (a) first ionization energy and (b) second ionization
energy.
*21.Why is the second ionization energy for a given element
always greater than the first ionization energy?
*22.What is the usual relationship between atomic radius and
first ionization energy, other factors being equal?
*23.What is the usual relationship between nuclear charge and
first ionization energy, other factors being equal?
*24.Going across a period on the periodic table, what is the
relationship between shielding and first ionization energy?BJKA
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