Name:________________________________ Period: ______
Unit 3 Study Guide: Electrons in Atoms
LIGHT
1. Which letter(s) represent one wavelength?
2. Which letter(s) represent the amplitude?
3. For a wave, high energy corresponds with _________________ wavelength and ___________________
frequency.
4. Which color of light has the highest energy:
a. green
c. yellow
b. orange
d. blue
5. TRUE or FALSE: If orange light has a longer wavelength than green light, it also has more energy.
6. In the visible light spectrum, which color of light has the most energy? Which color has the longest
wavelength?
7. Arrange the following types of electromagnetic radiation by their frequency (lowest frequency first): visible
light, radio, x-ray, infrared, gamma rays, and ultraviolet. (Hint: you may have to look up an
electromagnetic spectrum table on the internet)
8. What is the frequency of an electromagnetic wave that has a wavelength of 2.90 x 10-12 m?
9. What is the energy of a photon of light that has a frequency of 3.99 x 1019 Hz?
10. When an electron loses energy, it moves (closer / further away) from the nucleus and (releases / absorbs)
light.
11. Niels Bohr studied the energy released when atoms were subjected to energy in the form of an electric
current. He hypothesized that the energy was released by the electrons as they . . .
a. moved from a higher orbital to a lower
orbital
c. were attracted to another atom and
formed an ion.
b. moved from a lower orbital to a higher
orbital.
d. occupied a new orbital.
12. What does an emission spectrum look like?. What it can be used for?
13. Define ground state for an atom:
14. Define what it means for an electron to become excited:
15. Label the energy state of each atom below as ground state or excited.
16. Red light with a wavelength 700 nm is compared with blue light with a wavelength of 475 nm. Which color
of light has the highest energy? The highest frequency?
17. TRUE or FALSE: An element can be identified by the characteristic bright-line atomic emission spectrum it
can produce.
18. Define the word quantum:
ELECTRONS
1. Which model of the atom treats electrons as waves?
a. Bohr model
c. Quantum model
b. Plum Pudding model
d. Rutherford model
2. What is incorrect with the model of the atom (Bohr’s model) shown below.
3. How is an orbital different from an orbit?
4. What shape do orbitals in the s subshell have? In the p subshell? In the d subshell? In the f
subshell?
5. What is the difference between a 2p orbital and a 3p orbital?
a. the 3p orbital can only have one electron
b. the 3p can hold more electrons
c. the 2p has a slightly different shape
d. the 3p is at a higher energy level.
6. How many electrons can a single orbital hold? Do the electrons have the same or opposite
spins?
7. How many orbitals are in the p subshell? How many total electrons can a p subshell hold?
8. How many orbitals are in the d subshell? How many total electrons can fit in the d
subshell?
9. Using the diagram below, draw the Aufbau diagram for mercury (Hg).
6p
5d
4f
6s
5p
4d
4p
3d
ENERGY
5s
4s
3p
3s
2p
2s
1s
10. Write the full electron configuration for the following elements
a. silicon (Si):
b. iron (Fe):
c. titanium (Ti):
11. Write the abbreviated (noble gas) electron configuration for the following elements
a. radon (Rn)
b. strontium (Sr)
c. cadmium (Cd)
12. Write the electron configuration for phosphorus (P):

Which subshell in phosphorous is partially full of electrons?
13. Which element is represented by the following electron configurations:
a. 1s22s22p63s2
c. [Kr]5s24d2
b. 1s22s22p63s23p64s23d8
d. [Ne]3s23p5
14. Define valence electrons:
15. How many valence electrons do each of the following neutral elements have?
a. 1s22s22p63s23p5
d. Iron (Fe)
b. Aluminum (Al)
e. Lead (Pb)
c. Lithium (Li)
16. How many valence electrons does a neutral Bromine have?
a. 35
c. 7
b. 17
d. 79
17. Which element below has 6 valence electrons?
a. Fluorine (F)
c. Chromium (Cr)
b. Sulfur (S)
d. Neon (Ne)
18. In an electron-dot structure, the dots represent an atom’s . . .
a. valence electrons
b. core electrons
c. lowest energy
electrons
d. protons in the nucleus
19. Draw the electron-dot structure for the following elements:
a. carbon (C)
c. calcium (Ca)
b. tin (Sn)
d. fluorine (F)
20. List any three atoms that have the same number of valence electrons:
a. Draw their dot structures below:
21. Which type of electrons are represented by the dots in an electron-dot structure?
a. valence electrons
c. only s electrons
b. core electrons
d. both a and b
22. Use the figure below to answer the following questions:
a. How many total electrons does the above element have?
b. How many of those electrons are valence electrons?
c. What is the identity of the element?
d. Draw the element’s dot structure.