**The following problems are taken from T. L. Brown, H.
E. Lemay, B. E. Bursten, & J. R. Burdge, Chemistry: The Central Science,
Ninth ^{} Edition, Chapter 6.**

22**)** **It requires
a photon with a minimum energy of 4.41 x 10 ^{-19} J to emit electrons
from sodium metal. **

** (a) What is the minimum frequency
of light necessary to emit electrons from sodium via the photoelectric effect?**

** (b) What is the wavelength of this
light?**

** (c) If sodium is irradiated with
light of 439 nm, what is the maximum possible kinetic energy of the emitted
electrons?**

** (d) What is the maximum number
of electrons that can be freed by a burst of light whose total energy is 1.00
µJ? **

** **** **** **

28**)** ** For
each of the following electronic transitions in the hydrogen atom, calculate
the energy, frequency, and wavelength of the associated radiation, and determine
whether the radiation is emitted or absorbed during the transition:**

** (a) from n = 5 to n = 1**

** (b) from n = 4 to n = 2**

** (c) from the n = 4 to n = 6**

** (d) Does any of these transitions
emit or absorb visible light?**

** **

38**)** ** Calculate
the uncertainty in the position of:**

** (a) an electron moving at a speed
of (3.00 ± 0.01) x 10 ^{5} m/s**

** (b) a neutron moving at this same
speed **

** (c) What are the implications of
these calculations to our model of the atom?**

** **

46**)** ** Which
of the following are permissable sets of quantum numbers for an electron in
a hydrogen atom:**** **

** (a) n = 2, l = 1, m _{l}
= 1**

** (b) n = 1, l = 0, m _{l}
= -1**

** (c) n = 4, l = 2, m _{l}
= -2**

** (d) n = 3, l = 3, m _{l}
= 0 **

** For those combinations that are permissable,
write the appropriate designation for the subshell to which the orbital belongs
(that is, 1s, and so on).**

** **

56**)** ** What
is the maximum number of electrons in an atom that can have the following quantum
numbers: **

** (a) n = 2, m _{s} = -1/2,
**

** (b) n = 5, l = 3**

** (c) n = 4, l = 3, m _{l}
= -3**

** (d) n = 4, l = 1, m _{l}
= 1**

** **

74**)** ** The
light-sensitive substance in black-and-white photographic film is AgBr. Photons
provide the energy necessary to transfer an electron from Br ^{-} to
Ag^{+} to produce Ag and Br and thereby darken the film.**

** (a) If a minimum energy of 2.00
x 10 ^{5} J/mol is needed for this process, what is the minimum energy
needed by each photon?**

** (b) Calculate the wavelength of
the light necessary to provide photons of this energy.**

** (c) Explain why this film can be
handled in a dark room under red light.**

** **** **

**
**

** **