3.E: Electronic Structure (Exercises)
- Page ID
- 422490
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3.1: Light
- Describe the characteristics of a light wave.
- What is the frequency of light if its wavelength is 7.33 × 10−5 m?
- What is the frequency of light if its wavelength is 733 nm?
- What is the wavelength of light if its frequency is 8.19 × 1014 s−1?
- Place the following in order of increasing energy.
visible light, microwaves, radio waves, gamma radiation, x-rays, infrared light, ultraviolet light
- "5G" cell phone signal uses electromagnetic radiation (light) with wavelengths of 0.001 m - 0.01 m. What category (see the previous question) does this fall into?
Answers:
- Light has a wavelength and a frequency.
- 4.09 × 1012 s−1
- 4.09 × 1014 s−1
- 3.66 × 10−7 m
- radio waves < microwaves< infrared < visible < ultraviolet < x-rays < gamma
- microwave
3.2: Electron Behaviour
- Which of the following electron transitions would result in emission of light? ("n" is the shell)
a. n=1 → n=3
b. n=2 → n=1
c. n=2 → n=5
d. n=1 → n=7
- Which of the following electron transitions would result in absorption of light? ("n" is the shell)
a. n=5 → n=3
b. n=2 → n=1
c. n=2 → n=5
d. n=7 → n=6
- The hydrogen atom only has one electron. What shell represents the "ground state" for that electron?
- The hydrogen atom only has one electron. What shell(s) represents an "excited state" for that electron?
Answers
- Which of the following electron transitions would result in emission of light? ("n" is the shell)
b. n=2 → n=1
- Which of the following electron transitions would result in absorption of light? ("n" is the shell)
c. n=2 → n=5
- n = 1
- n = 2 through n = ∞
3.3 - 3.5: Electron Configurations
- How many subshells are completely filled with electrons for Na? How many subshells are unfilled?
- What is the maximum number of electrons in the entire n = 2 shell?
- Write the complete electron configuration for each atom.
- Si, 14 electrons
- Sc, 21 electron
- Write the complete electron configuration for each atom.
- Cd, 48 electrons
- Mg, 12 electrons
- Write the noble gas abbreviated electron configuration for each atom in question 3.
Answers
- Three subshells (1s, 2s, 2p) are completely filled, and one shell (3s) is partially filled.
- 8 electrons
- a. 1s22s22p63s23p2, b. 1s22s22p63s23p64s23d1
- a. 1s22s22p63s23p64s23d104p65s24d10, 1s22s22p63s2
- a. [Ne]3s23p2, [Ar]4s23d1
3.6: Periodic Trends
- State the trends in atomic radii as you go across (right) and down the periodic table.
- State the trends in IE as you go across and down the periodic table.
- Which atom of each pair is larger?
- Na or Cs
- N or Bi
- C or Ge
- C or B
- Which atom has the higher IE?
- Na or S
- Cl or Br
- Which atom has the greater magnitude of EA?
- Cl or F
- Al or Cl
Answers
- Across (right) = smaller radius/size, down = larger radius/size
- Across (right) = higher IE, down = lower IE
- Which atom of each pair is larger?
- Cs
- Bi
- Ge
- B
- Which atom has the higher IE?
- S
- Cl
- Which atom has the greater magnitude of EA?
- F
- Cl