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Chemistry 201/211
Worksheet 6
1.)
a.)
b.)
c.)
Fall 2004
November 11
Give the symbol of the element
In Group 14 that has the smallest atomic radius
In Period 3 that has the highest ionization energy
In Group 16 that has the lowest electronegativity
Oregon State University
C
Ar
Po
2.) Circle any true statement. A 3p orbital...
a.) can have an electron with a quantum number of l=2
no, p implies l=1
b.) can hold a maximum of 6 electrons yes, (2l+1) ml values times 2 () = 6ec.) can have an electron with a quantum number m l = -2 no, ml ranges from –l to +l
d.) can have a maximum of 3 unpaired electrons for an atom in the ground state
yes, there can be six electrons total in a p sublevel, if there are only three, they will
be arranged so that their spin is maximized ()
3.) The first two quantum numbers (n,l) of the highest energy electron of scandium in the
ground state are
a.) 3,0
b.) 3,1
c.) 3,2
d.) 4,0
e.) 4,1
Scandium is the first d (l=2) element in the periodic table. Being the first d, the
minimum n is 3.
4.) Which of these statements are true?
a.) Electrons have wave properties True
b.) Infrared radiation corresponds to higher energy radiation than visible light
False
The wavelength of infrared radiation is longer than visible light and E=hc/.
c.) Atoms emit light only at discrete, well-defined frequencies.
True
d.) The Pauli exclusion principle requires that only two electrons occupy a given orbital
False. Six electrons can occupy a p orbital, 10 can be in a d orbital, etc…
5.) Consider an iron, Fe, atom.
a.) Write its unexcited ground state electron configuration. 1s22s22p63s23p64s23d6
b.) Write its orbital diagram
() () ()()() () ()()() () ()()()()()
1s2
2s2
2p6
3s2
3p6
4s2
3d6
2+
c.) Write the abbreviated ground state configuration for Fe [Ar]3d6
d.) Compare the size of Fe with Fe2+; compare the size of Fe2+ and Fe3+ Fe>Fe2+
Fe2+>Fe3+
e.) What is the value of the highest n in the ground state? 4
f.) What is the value of the highest l 2
6.) Based on their positions in the periodic table, select the atom with the larger first
ionization energy from each of the following pairs:
a.) B, Cl
b.) N, P
c.) Hf, Cs
d.) O, N
e.) Ga, Ge
7.) What is the trend in first ionization energies as you proceed across the fourth period
from K to Kr? How does this compare with the trend in atomic sizes? The first
ionization energy increases as we go across the fourth period and the atomic size
decreases.
8.) Which of the following groups of elements is arranged in order of increasing
electronegativity?
a.) Si<Al<Br<Cl b.) Na<K<Ca<Ba c.) P<S<O<F d.) K<Rb<Cs<F e.) N<P<S<Cl
9.) Which of the following is expected to have the largest radius
a.) K+
b.) Ca2+
c.) S2d.) Cle.) They are all the same
10.) Write the Lewis dot structure of carbon suboxide (C3O2, three central carbons
flanked by two oxygen atoms). What would you predict its molecular geometry to be?
C3O2 is linear
11.) Draw the Lewis structures for the following compounds. Also indicate the
molecular geometry.
a.) NH3
b.) H2S
c.) PCl4+
d.) CO325.) CH3Cl
12.) Benzene (C6H6) consists of a six-member ring of carbon atoms with one hydrogen
bonded to each carbon. Write Lewis structures for benzene, including resonance
structures.
13.) Which one of the following species would have a Lewis structure most like that of
SO2?
a.) CO2
b.) NO2
c.) NO2+
d.) NO2e.) SiO2
How many unshared electron pairs (lone pairs) are in a molecule of SO2? 2
What is its molecular geometry? bent
14.) The Lewis structure
represents…
a.) NO2
b.) NO2- c.) NO2+
d.) both NO2- and NO2+ e.) NO2, NO2- and NO2+
There are 18 e- that are used in this Lewis structure (3 bonds * 2 = 6e- + 12 lone pair e-).
Nitrogen has 5 e- and oxygen has 6 e- that total to 17e-. Therefore, an extra electron was
needed making an overall negative one charge.