__Unit 4 Review __

Section I - Problems (Given h = 6.626 x 10^{-34} J^{.}s)

1.
The speed of light, c, equals __ 3.00 x 10 ^{8} __ m/s.

2.
What is the frequency of a wave with a wavelength of 3.5 x 10^{8}
m?

c = ^{.} n 3.00 x 10^{8}
m/s = 3.5 x 10^{8} m ^{.} n n = 0.86 ^{1}/_{s} (or Hz)

3. What is the energy of a photon with a
frequency of 5.41 x 10^{-7 1}/_{s}?

E = h ^{.} ^{-34} J ^{.}^{ }s)
^{.} (5.41 x 10^{-7 1}/_{s}) E = 3.58 x 10^{-40} J

4. Substitute, rearrange, and write an equation
that relates E, h, c, and l.

__ c __ = __ ____l____ ^{.} n__

l l l

1.
Label both ends of the spectrum with high/low frequency, high/low
energy, and long/short wavelength

Long wavelength __radio
waves microwaves infrared light ROYGBIV ultraviolet
light x-rays
gamma rays__ short
wavelength

Low frequency high frequency

Low energy high energy

3. Which has a shorter wavelength, radio or
ultraviolet?

4. Which has a lower frequency, yellow or green
light?

5. In the equation E = hn, energy and frequency are __ directly____ __ proportional.

6.
In the equation c = ln, wavelength and frequency are __ inversely____ __ proportional.

7.
The symbol for wavelength is __ ____l____ __.

8.
__ Frequency equals__
the number of waves that pass a point per second.

9.
Electrons give off energy in the form of a __ photon____ (or quantum) __ when returning to the ground state.

10.
Which scientist proposed the idea that electrons travel around the
nucleus in fixed paths?

11. When an electron moves
from the ground state to the excited state, energy is __ absorbed____ __.

12. Bohr chose the element __ hydrogen____ __ to
prove his theory.

13. The dual wave-particle
nature of electrons describes how the electrons in atoms can behave as

__ waves and__ __ particles __.

Section III - Electrons

1. What is an electron
cloud? Area
around the nucleus where electrons are located

*2. Who proposed the uncertainty principle? Heisenberg

*3. Who is credited with the
idea that electrons are placed in the lowest energy level first? Aufbau

*4. What rule requires that
each of the "p" orbitals (at a particular
energy level) receive one electron before any

of the orbitals
can have two electrons? Hund’s Rule

5. What is the maximum number
of electrons in any orbital? 2

6. The principal quantum
number, n, indicates the __ energy____ level __.

7. The maximum number of
electrons in an energy level can be determined by the equation
__ 2____ n ^{2} __

That means the maximum number of electrons in the 3rd energy level is

8. The number of sublevels in
any energy level can be determined by __ the____ number of the energy level __.

9. The number of orbitals in an energy level can be determined by the equation __ n ^{2}__

So, the 3rd energy level has

is/are "d" orbitals)

10. List the four sublevels
according to increasing energy. s à p à d à f

11. The "s"
sublevel is shaped like a __ sphere____ __ and
has __ 1 __ orbital.

12. A "p" sublevel is
shaped like a __ dumbbell____ __ and
has __ 3 __ orbitals.

13. The "d"
sublevel has __ 5____
__ orbitals
and the "f" sublevel has __ 7 __ orbitals.

Section IV - Electron configuration, noble gas configuration, valence electrons, orbital notations

1. What is the electron configuration
for phosphorus? 1s^{2} 2s^{2} 2p^{6} 3s^{2}
3p^{3}

2. How many total electrons are in a neutral atom of phosphorus? 15

3. Write the noble gas
configuration for phosphorus. [Ne] 3s^{2} 3p^{3}

4. What is the highest occupied energy level for phosphorus? 3

5. What is the atomic number of phosphorus? 15

6. Draw the orbital notation
for phosphorus. __hi__ __h __ __h __ __h
__ 3s 3p

7. How many electrons are in the highest occupied energy level of phosphorus? 5

8. How many unpaired electrons does phosphorus have? 3

9. How many inner-shell electrons does phosphorus have? 10

10. In which orbitals are the inner-shell electrons located? 1s, 2s, 2p

11. Draw the electron dot
diagram for phosphorus. .

:
P .

.

Section V - Quantum numbers (Honors level only)

1. How many electrons can be
described by the quantum numbers n = 3 and l = 1? 6

2. How many electrons in an
atom can have the quantum numbers n = 2 and l = 3? 0

3. How many "d" orbitals have the value n = 3? 5

4. How many electrons in an atom have the quantum numbers n = 4 and l = 2? 10

5. Which of the following
sets of quantum numbers does NOT represent a possible set of quantum numbers
for a

hydrogen atom? (There may be more than one
correct answer.)

__ n __ __
____l____ __ __
m __ __ s
__
(A)
4
8
-4 p;

(B) 6 5 -5 p;

(C) 3 2 2

(D) 6 0 1