E
hc

per photon!
Energy of a single photon: 4.67 x 10-18 J / 10 = 4.67 x 10-19 J
hc

E
nm
6.63 10 34 Js 3 108 ms 1
 9

19
10 m
4.67 10 J
= 426 nm
Assuming the Bohr model of the atom;
calculate the wavelength of the band in
the spectrum of atomic hydrogen for the
transition involving orbits n = 2 and n = 3.
a.410 nm
b. 656 nm
c. 486 nm
d. 434 nm
 1
1 
1 
1
E  2.18 x10 J  2  2   2.18 x1018 J  2  2   3.03 x1019 J
n

2 
3
 f ni 
34
6.63
x
10
J  s   3 x10 ms 
hc

hc
E
 

 6.56 x107 m  656nm
19

E
3.03 x10 J
18
h  6.63x1034 J  s; c  3 x108
Department of Chemistry and Biochemistry
m
s
In a multielectron atom, which quantum
number combination (n,l,ml, ms) is associated
with the electron with the same energy as
one with n=3, l=1, ml = 0, ms = +1/2 ?
a. 3, 1, 0, -1/2
c. 3, 0, 1, +1/2
Department of Chemistry and Biochemistry
b. 2, 1, 0, +1/2
d. 3, 1, 1/2, -1/2
Calculate the change in energy of a
hydrogen atom that emits a photon with
a frequency of 2.5x1015 s-1.
a. 1.6 × 10-18 J
b. -1.6 × 10-18 J
c. 6.1x1017 J
d. - 6.1x1017 J
E  h   6.63 x1034 J  s   2.5 x1015 s 1   1.6 x1018 J
h  6.63x10
34
Department of Chemistry and Biochemistry
J  s; c  3 x10
8 m
s
Carbon has the electron configuration 1s22s22p2. The following
diagrams show the arrangements of two electrons in the 2p orbital of
carbon.
.
i
.
ii
iii
iv
Select all the electron configurations that are NOT allowed
for carbon.
a. i only
b. i, iii
c. iii only
d. iii, iv
Which electron configuration(s) lead(s) to the most
stable carbon atom?
a. i only
b. i, ii
Department of Chemistry and Biochemistry
c. iv only
d. iii, iv
The ground state electron configuration
of Fe is [Ar]4s23d6. What is the electron
configuration of iron in FeCl3 ?
a. [Ar]4s23d3
c. [Ar]4s23d4
Department of Chemistry and Biochemistry
b. [Ar]3d6
d. [Ar]3d5
(i)
( ii )
( iii )
( iv )
What is the maximum number of electrons that a subshell
that contains orbital (iv) can have?
a. 2
b. 4
c. 5
d. 10
Which of the following statements is NOT correct
a. Orbital ( i) always has smaller energy than orbital (iv).
b. Orbital (ii) and orbital (iii) can have different principal quantum number n.
c. Orbital (i) can be associated with any principal quantum number n.
d. ml = +2, ms = -1/2 is a possible combination of quantum numbers for
orbital (iv).
Department of Chemistry and Biochemistry
What is the valence electron configuration of elements in group 3A of the
periodic table?
a. ns1np2
b. ns2np1
c. ns2np2
d. ns2np3
Which of the following pairs of ions and atoms are isoelectronic?
[He]2s22p6 or [Ne]
[Ar]4s23d104p6 or [Kr]
[He]2s22p6 or [Ne]
I. O2- and Na+
II. Sr2+ and Kr
III. F- and Ne
a. I. only
b. I. and II.
c. none
d. all
Horxn = [Hof [H2SO4 (l)] – [Hof [H2O] (g) + Hof [SO3] (g)]
Hof [H2SO4 (l) = Horxn + [Hof [H2O] (g) + Hof [SO3] (g)]
= -177.0 kJ + [-241.8kJ - 395.2kJ] = -814 kJ
G = H - TS