Name______/ Period: ______
Date: ______/ Subject: Chemistry
CHEMISTRY / CODE: SCS21
2014-2015 SCHOOL YEAR / INSTRUCTOR: Ms. Bui
CLASSROOM: 510 / LAB ROOM: 506

LAB 02

ELECTRON CONFIGURATION

Name______/ Period: ______
Date: ______/ 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).
  1. What is the maximum numbers of electrons in Energy Level 1 (shell)? ______
  2. If the electron configuration is 2-8-4,
  3. How many energy levels does the element have? ______
  1. What is the total number of electrons? ______
  1. What is the maximum number of electrons in the outside shell? ______

Materials:

Beans

Atom with Electron Shells (per group)

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 Configuration / Number of Shells / Diagram / Total Number of Electrons
Carbon / 2-4 / 2 / / 6
Sodium
Calcium
Neon
Silicon
  1. 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)

  1. O
  2. Li
  3. K
  4. Al
  5. B
  6. Cl

Critical Thinking:

  1. A mystery element has an electron configuration of 2-8-16-2 in its ground state. This should take about 5 minutes. (____/9 points)
  1. Identify the number of protons ______(2 points)
  2. What is the name for the mystery element ______(2 points)
  3. 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).

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.
  1. 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

  1. 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): ______

  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. ( _____/15 points)

Element / Condition / Electron Configuration / Excited Electron Configuration / Diagram
Carbon / 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

Post Lab Questions: (all responses should be in complete sentences)Should take 10 minutes (______/10points)

  1. Explain the difference between ground state and excited state (3 points)?
  1. 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).
  1. 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 Class1Lab 02 – Electron Configuration