CHEMISTRY
2014-2015 SCHOOL YEAR
CLASSROOM: 510
CODE: SCS21
INSTRUCTOR: Ms. Bui
LAB ROOM: 506
LAB 02
ELECTRON CONFIGURATION
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
Instructions: Take 5 minutes to read the Pre-Lab and answer the 2 questions below (10 points)
PRE-LAB: ( _____/8 points)
Firework has been employed to celebrate holidays and events throughout the history of the world. The
first firework display dates back to China in the 7th century. The largest single coordinated firework
display occurs in Dubai in 2014 in which over 500,000 fireworks were burned.
To produce the colorful display during a firework display metal salts (such as calcium chloride and
sodium nitrate) are heated. The atoms of each element then absorb the energy resulting in the electrons
within the atom to jump from the ground state (lowest energy state to an excited state (higher energy
state). Electrons in the excited state tend to release the energy to return back to the ground state. When
energy is released, light is emitted. The color of the light depends upon the element and the amount of
energy. Examples: Calcium chloride emits an orange color, strontium carbonate emits a bright red color
and copper chloride emits a blue color.
When the electrons jump from a ground state to an excited state, the
electron configuration of the electrons also changes. Electron
configuration of an atom describes the orbitals occupied by electrons
on the atoms. Electrons in the ground state (lowest energy state) are
usually added to the lowest energy level (shell) first. In other words,
the lowest energy level is filled before moving onto the next energy.
Each energy level has a maximum numbers of electrons (see diagram).
Figure 1
1. What is the maximum numbers of electrons in Energy Level 1
(shell)? ___________________
2. If the electron configuration is 2-8-4,
a. How many energy levels does the element have? ___________
b. What is the total number of electrons? _______________________
c. What is the maximum number of electrons in the outside shell? ___________________
Materials:
Beans
Atom with Electron Shells (per group)
Lab Rubric
Teacher’s Grade:

Pre-Lab (8 points): __________________

Demonstration (10 points): _____________

Accuracy (72 points):__________________
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
Ground State Electron Configuration
1. For each element, use the beans and the Electron Shell template to help you complete the table
below. This should take you 10 minutes to complete. ( _____/16 points)
Element
Electron
Number of
Diagram
Total Number of
Configuration
Carbon
2-4
Shells
2
Electrons
6
Sodium
Calcium
Neon
Silicon
Ms. Bui’s Chemistry Class
2
Lab 02 – Electron Configuration
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
2. Demonstration: Ms. Bui will ask you to demonstrate how you fill in the electron shells. She will
ask you to demonstrate 2 from the following elements.
This should take 5 minutes (_________/10 points)
a. O
b. Li
c. K
d. Al
e. B
f. Cl
Critical Thinking:
3. A mystery element has an electron configuration of 2-8-16-2 in its ground state. This should take
about 5 minutes. (____/9 points)
a. Identify the number of protons _________________________________________ (2 points)
b. What is the name for the mystery element ____________________________ (2 points)
c. Using CER, explain how you came up with the answer. You must use the word electron in
your answer. The answer must be at least 2-3 complete sentences (5 points).
Ms. Bui’s Chemistry Class
3
Lab 02 – Electron Configuration
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
Excited State Electron Configurations
Electrons can jump from the lowest energy state (ground state) to that of a higher energy state
(excited state). Electrons can jump one or more energy state. This means that the energy levels
are no longer being filled in starting with the lowest energy and going up.
For example, sodium in the ground state is 2-8-1. One excited
state configuration could be 2-7-2. In this example, one electron
has jumped from the second energy level to the third.
Rules for excited state configurations:
- The total number of electrons has not changed.
- No energy level can have more than its maximum
number of electrons.
When electrons loses energy, the electron may fall to a lower
energy state (can fall one or more energy level). Different colors
may be emitted depending upon the number of energy levels
that the electrons fall.
4. Instruction: Using the periodic table, identify if the element is in its ground state or in an excited
state by circling the right choice. This should take 5 minutes. (___________/6)
a) Nitrogen (2-5):
ground state/excited state
b) Iron (2-7-15-2):
ground state/excited state
c) Potassium (1-8-9-15):
ground state/excited state
d) Lithium (1-2):
ground state/excited state
e) Silver (2-8-18-18-1):
ground state/excited state
f) Chromium (2-8-12-2):
ground state/excited state
5. Instruction: Using the periodic table, write the ground state for the given excited electron
configuration. This should take 5 minutes. (___________/6)
g) Aluminum (2-7-4):
________________________________________________
h) Arsenic (1-8-18-6):
________________________________________________
i) Chlorine (2-6-9):
________________________________________________
j) Copper (2-7-18-2)
________________________________________________
k) Sulfur (2-6-8):
________________________________________________
l) Iodine (2-8-16-18-9):
________________________________________________
Ms. Bui’s Chemistry Class
4
Lab 02 – Electron Configuration
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
6. For each element, use the beans and the Electron Shell template to help you complete the table
below. This should take you 10 minutes to complete. ( _____/15 points)
Element
Condition
Electron
Excited Electron
Diagram
Configuration
Carbon
Configuration
One electron
jumps from the
first to second
energy level
Sodium
One electron
jumps from the
first to third
energy level
Calcium
Two electrons
jumps from the
second energy
level to the fourth
energy level
Fluorine
One electron
jumps to the
second level
Silicon
One electron
jump to the third
energy level
Ms. Bui’s Chemistry Class
5
Lab 02 – Electron Configuration
Name_______________________________________
Date: ______________________________________
Period: _____________________________________
Subject: Chemistry
Post Lab Questions: (all responses should be in complete sentences) Should take 10 minutes (_______/10
points)
1. Explain the difference between ground state and excited state (3 points)?
2. The electron configuration for the element fluorine is both 2-7 and 1-8. Explain how the
movement of electrons makes the existence of both electron configurations possible (3 points).
3. Looking at Groups 1 and 2 on the Periodic Table, explain the trends you see in the electron
configuration for the elements belonging to these groups (4 points).
Ms. Bui’s Chemistry Class
6
Lab 02 – Electron Configuration