Properties of Light

Part 1 - Select the best answer

1.  Which has a longer wavelength, orange or violet light?
2.  Which has a higher energy, x-rays or gamma rays?
3.  Which has a lower frequency, radio waves or green light?
4.  Which has the shortest wavelength, violet or ultraviolet light?
5.  Which has lower energy, infrared light or x-rays?

Part 2 - Fill in the blanks

6.  _______________ formed a theory to explain the structure of an atom by revising physical theories.
7.  As the energy level increases, the amount of energy an electron will possess _______________.
8.  Electrons give off energy in finite amounts called _______________ when returning to the ground state.
9.  When this energy is released in the form of light it is called a _______________.
10.  Electromagnetic radiation travels through space as _______________.
11.  The speed of light = _______________ (give number and units)
12.  The symbol for wavelength is _______________.
13.  _______________ equals the number of waves passing a point per second.
14.  In the equation c =
ln, c represents _______________, n represents _______________, and

l represents _______________.
15.  In the equation c =
ln, l and n are _______________ proportional.
16.  In the equation E = h
n, h represents _______________ and E represents _______________.
17.  In the equation E = h
n, E and n are _______________ proportional.
18.  Bohr chose the element _______________ to prove his theory.

Part 3 - True or False

19.  Electrons may regularly occupy spaces between orbitals.
20.  The varying wavelengths on the electromagnetic radiation spectrum travel at different speeds.

EM SPECTRUM, WAVELENGTH, FREQUENCY, AND ENERGY

1.) Look at the EM spectrum on p. iv of the reference tables to answer this question.

As you move across the visible light spectrum from red to violet

(A)    Does the wavelength increase or decrease?

(B)     Does the frequency increase or decrease?

(C)    Does the energy increase or decrease?

2.) A beam of microwaves has a frequency of 1.0 x 109 Hz.  A radar beam has a frequency of 5.0 x 1011 Hz.

(A)    has a longer wavelength?

(B)     is closer to visible light on the EM spectrum?

(C)    is closer to x-rays in frequency value?

3.) What is the frequency of an EM radiation wave if its wavelength is 3.6 x 10-9 meters?

4.) A beam of EM radiation has a wavelength of 4.257 x 10-7 cm.  What is its frequency?

5.) A photon of light has a wavelength of 3.20 x 105 meters.  Find…

(A) the frequency

(B) the energy

(C) the region of the EM spectrum/type of radiation

6.) A photon has an energy of 4.00 x 10-19 J.  Find…

(A) the frequency

(B) the wavelength

(C) the region of the EM spectrum/type of radiation

7.) A bright line spectrum contains a line with a wavelength of 518 nm.  Determine…

(A) the wavelength in meters

(B) the frequency

(C) the energy

(D) the color

*8.) Cobalt-60 is an artificial radioisotope that is produced in a nuclear reactor for use as a gamma ray source in the treatment of certain types of cancer.  If the wavelength of the gamma radiation from a cobalt-60 source is 1.00 x 10-3 nm, calculate the energy of a photon of this radiation.

ELECTRON ARRANGEMENT

1.  What is an electron cloud?

2.  Name the three major divisions within an electron cloud with respect to the energy of an electron.

3.  What letter represents the principal quantum number?

4.  What does the principle quantum number tell about an electron?

5.  What formula is used to determine the maximum number of electrons that can occupy any energy level?

6.  What is the maximum number of electrons for each of the following?
(A) 1st energy level        (B) 4th energy level        (C) n = 3        (D) n = 5

7.  Energy levels are divided into _______________.

8.  How can we determine the possible number of sublevels in any energy level?

9.  Name the four primary sublevels in order of increasing energy.

10.  Circle the sublevel that represents the lowest energy in each pair.
(A) 1s or 2s            (B) 2s or 2p            (C) 4f or 4d            (D) 3d or 4s            (E) 7s or 5d
(F) 6s or 4s            (G) 4p or 5p            (H) 3s or 3d            (I) 2p or 3s

11.  Sublevels are divided into _______________.

12.  Each orbital can hold up to _______________ electrons.

13.  Sketch the shapes of the orbitals for the sublevels listed.
(A) s:                                (B) px:                                (C) py:                                (D) pz:

14.  How many orbitals are in each sublevel?
(A) s _______________    (B) p _______________    (C) d _______________    (D) f _______________

ELECTRON DOT DIAGRAMS

 ELEMENT ELECTRON CONFIGURATION NOBLE GAS CONFIGURATION HIGHEST OCCUPIED ENERGY LEVEL # OF VALENCE ELECTRONS ORBITAL NOTATION OF H.O.E.L. ELECTRON DOT DIAGRAM 1.   EX magnesium 1s2 2s2 2p6 3s2 [Ne] 3s2 3 2 _hi_   3s : Mg 2. carbon C 3. sulfur S 4. barium Ba 5. nickel Ni 6. oxygen O 7. arsenic As 8. lead Pb 9. lithium Li 10. neon Ne 11. bromine Br 12. sodium Na 13. chlorine Cl 14. argon Ar 15. calcium Ca 16. zinc Zn 17. potassium K 18. iodine I 19. cobalt Co 20. nitrogen N 21. fluorine F 22. iron Fe 23. phosphorus P 24. aluminum Al

Unit 4 Review

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

1.  The speed of light, c, equals ____________________ m/s.

2.  What is the frequency of a wave with a wavelength of 3.5 x 108 m?

3.  What is the energy of a photon with a frequency of 5.41 x 10-7 Hz?

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

Section II - Electromagnetic Spectrum

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

radio waves       microwaves     infrared light        ROYGBIV           ultraviolet light   x-rays        gamma rays

2.  Which has a higher energy, gamma or x-rays?

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 ____________________ proportional.

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

7.  The symbol for wavelength is _____.

8.  ____________________ equals the number of waves that pass a point per second.

9.  Electrons give off energy in the form of a ____________________ 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 ____________________.

12.  Bohr chose the element ____________________ to prove his theory.

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

Section III - Electrons

1.  What is an electron cloud?

2.  Who proposed the uncertainty principle?

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

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?

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

6.  The principal quantum number, n, indicates the ____________________.

7.  The maximum number of electrons in an energy level can be determined by the equation ________________
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 ____________________.

9.  The number of orbitals in an energy level can be determined by the equation ____________________.
So, the 3rd energy level has _____ orbitals.  (_____ is/are "s" orbitals, _____ is/are "p" orbitals, and _____
is/are "d" orbitals)

10.  List the four sublevels according to increasing energy.

11.  The "s" sublevel is shaped like a ____________________ and has _____ orbitals.

12.  A "p" sublevel is shaped like a ____________________ and has _____ orbitals.

13.  The "d" sublevel has _____ orbitals and the "f" sublevel has _____ orbitals.

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

1.  What is the electron configuration for phosphorus?

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

3.  Write the noble gas configuration for phosphorus.

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

5.  What is the atomic number of phosphorus?

6.  Draw the orbital notation for phosphorus.

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

8.  How many unpaired electrons does phosphorus have?

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

10.  In which orbitals are the inner-shell electrons located?

11.  Draw the electron dot diagram for phosphorus.