Chem 481. Chapter 1. Atomic Stucture And Periodic Table Worksheet With Answers
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10CHEM 481. Chapter 1. Atomic stucture and periodic table. Answers
The material on Lewis structures and VSEPR is covered in greater detail in all General Chemistry text books. You are strongly
encouraged to consult such a book. Also, consider viewing the Kotz and Treichel CD-ROM (Saunders Interactive Chemistry
rd
disc.) The relevant sections in the Kotz and Treichel textbook, 3
edition, are 9.3 to 9.7 (p. 402 - 450). This book is on reserve for
Chem2810 in the library. It is essential that you practice Lewis and VSEPR structures with many different examples. You must be
able to do these problems quickly and reliably, or else the whole procedure is not very much use. This comes only by much
practice.
1.
Using a copy of the blank periodic table distributed with the lecture notes, and without consulting references, identify
the s, p, d and f groups. Enter as many element names and symbols as you remember easily.
2.
Define the following terms: (a) rare earth elements; (b) van der Waals radius; (c) effective nuclear charge; (d) second
ionization energy; (e) enthalpy of electron attachment (electron affinity).
(a) The rare earth elements are another name for the lanthanides; “earth” is an Alchemical name for “oxide”, so these are
the elements of the rare oxides, and indeed the natural abundance of these elements is uniformly low.
(b) A van der Waals’ radius refers to the size that atom appears to have to a neighbouring atom when they come in contact
without being able to form a chemical bond. Johannes van der Waals obtained the first estimate of this parameter by
solving his equation for real gases, of the form:
2
n
[
]
+
−
=
P
a
V
bn
nRT
V
where the b parameter reflects the volume per unit atom or molecule of a real gas atom or molecule.
(c) The effective nuclear charge experienced by any electron in an element reflects the net of the actual nuclear charge
(given by the number of protons) and the screening effect of the other electrons in that element’s electron configuration. It
is often called Z*, and is given by Slater’s equation: Z* = Z – S, where S is the screening term.
(d) The second ionization energy is defined as the enthalpy required to remove a single electron from the gas-phase
monocation of any element to yield the gas-phase dication of that same element, algebraically as:
+
2+
–
(g) ∆H° = 2
nd
M
(g)
M
(g) + e
I.E.
(e) The (first) enthalpy of electron attachment is defined as the enthalpy required to add an electron to a gas-phase atom of
any element to give the gas-phase monoanion of that element, algebraically as:
(g) ∆H° = 1
–
–
st
M (g)
+ e
(g)
M
E.A.
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education