Chapter 7 Practice Problems [Watts, Fall 2008.]
Problem 1.
The false statement is (b). The reason is that cathode rays are electrons. Therefore they
are independent of element. See pages 260-262.
Problem 5
Amplitude is not mathematically related to the other quantities. The other quantities are
related to each other according to: u = λυ. The meanings are: u is the speed; λ is the
wavelength; and υ is the frequency. If we are talking about electromagnetic waves, the
speed is the speed of light, which is given the symbol c. See page 268.
Problem 18
The set of quantum numbers given (n = 2, l = 2, ml = 0) is not allowed.
Reason: since n = 2, the largest allowed value of l is 1 (i.e. n – 1).
Other notes: (1) There is no such thing as a 2d orbital; (2) a 2p orbital has n = 2, l = 1.
Problem 32
λ = 11.5 nm = 11.5 x 10-9 m = 1.15 x 10-8 m
116
8
18
1061.2
1015.1
10998.2
s
m
sm
c
Region of spectrum: ultraviolet. See page 269.
λ = 9.32 cm = 9.32 x 10-2 m
19
2
18
1022.3
1032.9
10998.2
s
m
sm
c
Region of spectrum: radiowaves. See page 269.
λ = 1.93 x 106 m
12
6
18
1055.1
1093.1
10998.2
s
m
sm
c
