Worksheet Electrons

Chemistry Worksheet: Light : Chapt 13 : p. 372-375 Page 2
1. Arrange the following electromagnetic radiations in order of decreasing wavelength.
a. Infrared radiation from a heat lamp, (b) ultraviolet radiation from the sun, (c) dental X-rays,
(d) the signal from a short wave radio station, (e) green light _______________
2. Arrange the radiation from prob. 1 in order of increasing energy. ________________
Constants and Equations you will need:
!= “nu” = frequency of radiation, Hz, 1/sec or sec –1 " = “lambda”= wavelength of radiation
h = Planck’s constant = 6.63 x 10 –34 Joules–sec c = 3.00 x 10 8 m/sec (speed of light)
c = ! " (Relationship between E = h ! or E = h c (Energy of a photon of light)
frequency and wavelength) "
Metric conversions: 1 x 10 9 nm = 1 m 1 x 10 6 µm = 1 m 1 x 10 3 Hz = 1 kHz
3. a. What is the wavelength in m of radiation whose frequency is 1.5 x 10 15 sec –1 (2x10 –7 m)
b. Convert this wavelength to nm. (200 nm)
c. In what part of the EM spectrum is this radiation ________
d. Does this radiation have a longer or shorter wavelength than red light ________
4. What is the frequency of green light with a wavelength of 5.20 x 10 –7 meters (5.77x10 14 Hz)
What part of the EM spectrum is this radiation
5. Radio Station WTIC AM in Hartford, CT, broadcasts at a frequency of 1080 KiloHz.
a. What is this frequency in Hz (1.08 x10 6 Hz)
b. What is the wavelength in m of these radio waves (278 m)
c. Convert this wavelength to cm. (2.78x10 4 cm)
6. What is the energy of a photon of microwave radiation with frequency = 7.6 x 10 11 sec –1
(5.04x10 –22 J)
7. What is the energy of a photon of radiation with a wavelength of 6.0 x 10 –5 m Is this more or
less energy than that of Question 6 (3.32 x 10 –21 J)
8. What is the energy of a photon of light with a wavelength of 4.5 x 10 –2 nm What part of the
EM Spectrum is this photon (hint: change nm to m first). (4.42 x10 –15 J)

Electron configurations and notations: p. 367-370 Page 3
Fill in this chart for the electron configuration of these elements
Symbol Atomic Electron configuration Orbital notation (do to Ar only)
_________number_____________________________________________________________________
N 7 1s 2 2s 2 2p 3 #$ #$ # # # (7 arrows)
(7 electrons) (superscripts total 7) 1s 2s 2p
_________________________________________________________________________________
H 1
_________________________________________________________________________________
He 2
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Be 4
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C 6
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O 8
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*Ne 10
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Mg 12 [Ne]
_________________________________________________________________________________
Al 13 [Ne]
_________________________________________________________________________________
P 15 [Ne]
_________________________________________________________________________________
*Ar 18 [Ne]
_________________________________________________________________________________
1. How many electrons are in the 2nd energy level of : (Add 2s and 2p together!)
Be N O Ne Mg Ar
2. How many electron pairs ( #$ ) are in :
Be N O Ne
You may use the "core method" for the following. Be sure to start with the previous *Noble
Gas. Omit the orbital notation!
Sym. Atomic Electron config. Symbol Atomic Electron config.
number (omit orbitals) number (omit orbitals)
_________________________________________________________________________________
K 19 [ Ar ] 4s 1 Co 27
_________________________________________________________________________________
Ca 20 Br 35
________________________________________________________________________
Sc 21 *Kr 36

Electron configurations and notations: continued Page 4
Sym. Atomic Electron config. Symbol Atomic Electron config.
number (omit orbitals) number (omit orbitals)
_____________________________________________________________________________________
Rb 37 [Kr] Nd 60
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Zr 40 Er 68
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Sn 50 Ir 77
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*Xe 54 Bi 83
__________________________________________________________________________________
Ba 56 [Xe] *Rn 86
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Cr 24 (Exception to rule: Will be done in class: Pay attention!)
__________________________________________________________________________________
Questions with Electron configurations
Use your answers from above and the previous worksheet to help you answer Q. 1 – 5
1. How many electrons are in the outside, or highest occupied energy level of the following: (Hint:
Add together the highest s and p sublevels!) Example: Kr has 8 (2 in 4s, 6 in 4p)
C P Sc Br Rb Xe
2. Which of these has an octet (s 2 p 6 ) as its outer electron configuration
Mg Ar Sc Kr Sn Xe
3. Which of these has its 3rd energy level completely filled (Hint: 3s 2 3p 6 3d 10 )
P Ar Ca Co Br Kr Rb
4. Which of these has its 4th energy level completely filled(What sublevels are in 4th level)
Kr Sn Xe Nd Er Ir Bi
5. How many energy levels are occupied in each of the following (Short cut: Row number on
periodic table)
C Mg Ar K Br Rb Zr Xe Nd Bi
6. Which of these orbital notations is a correct, ground state configuration What rule do the
others violate
a. # # #$ # # # c. # $# #$ # # #
1s 2s 2p 1s 2s 2p
b. # $ #$ # # d. # $ #$ # $ #
1s 2s 2p 1s 2s 2p
1) 4, 5, 2, 7, 1, 8; 2) Ar, Kr, Xe (noble gases); 3) Br, Kr, Rb; 4) Ir, Bi; 5) 2, 3, 3, 4, 4, 5, 5, 5, 6, 6) b correct; a& c violate
Pauli Prin. ; d violate Hund's rule

Review questions: Electrons : p. 361-383 Page 5
1. What is the wavelength in meters and cm of waves with a frequency of 5 x 10 6 sec –1 . What
part of the EM spectrum is this
(60 m, 6000 cm)
2. What is the wavelength and energy of a photon of with a frequency of 5.80 x 10 14 sec -1
What color is the photon (3.85 x 10 -19 J)
3. Consider the orbital notation for Oxygen: #$ #$ #$ # #
1s 2s 2p
The "2" in 2s and 2p stands for the ___________, the "p" and "s" stand for the ________
the lines above the "2p" stand for the _____________, and the arrows _____________.
4. Consider the 4th energy level: What sublevels are found there _______________
How many orbitals of each type of sublevel are there ________________________
How many electrons can occupy each of these sublevels___________________
How many electrons are needed to completely fill the 4th energy level _____
5. Circle the correct filling order for the sublevels for elements in the 4th series (K - Kr).
4s 4p 4d 4s 3p 4d 4s 4d 4p 4s 3d 4p
6. Give the electron configuration (1s 2 ) and orbital notation (arrows) for the following:
B _____________ ______________ S
Ni
Omit orbital ______________________
___________ _______________
Calculatrivia for electron configurations: Solve the following.
a. Number of 4s electrons in Sc ______ b. Number of electrons in H ______
c. Highest energy level occupied in Neodymium (Nd) ______
d. Atomic number of the lowest element with an octet ______
e. Atomic weight of element with configuration 1s 2 2s 2 2p 6 3s 1 ______
f. Number of electrons in the highest energy level of Br ______
g. Number of electron pairs in oxygen ______
h. Number of orbitals in the entire 3rd energy level ______
j. Theoretical maximum number of electrons in the 5th energy level (2n 2) ______
k. Theoretical number of sublevels in the 7th energy level ______
m. Lowest energy level with a d sublevel ______
Substitute your answers into the following equation. Then show me the element with this
atomic number
g
(( h m ) – e ) ( d – b) + ( j – ( k f ))
c a
Ans to calculatrivia: a. 2; b. 1; c. 6; d. 10; e. 23; f. 7; g. 3; h. 9; j. 50; k . 7; m. 3