Electrons and Energy Levels Activity

Purpose: To observe and compare different Bohr Models to gain a better understanding of atomic structure and to see the relationship between the periodic table, valence electrons, and energy levels.

Background: Electrons are located in a region outside the atomic nucleus called the electron cloud. The electron cloud is made up of different energy levels. Each energy level can hold only a certain number of electrons. The energy levels are always filled in order. The outermost energy level holds the valence electrons. These valence electrons are found only when the energy levels closest to the nucleus are completely filled. Valence electrons are the only electrons involved in chemical reactions and bonding.

Materials: poster board Bohr models of atoms, beads attached to represent valence electrons.

Procedure:

  1. With the use of your periodic table, put the Bohr models in order, just as they appear in the first 3 rows on the periodic table.
  1. Complete the table with the correct information and answer the following questions.

Name:______Class:______Date:______

Electrons and Energy Levels Activity

Data Table and Questions:

Element / Atomic Number / Row in periodic table / Column in periodic table / # of valence electrons / # of energy levels
He
Li
Be
O
F
Ne
Na
Mg
Cl
Ar
  1. Look at the models of elements that appear in the same vertical column. What do you notice about the number of valence electrons when comparing these to each other and to the group they are found in?
  1. Look at the models of elements that appear in the 2nd and 3rd rows. What is happening to the number of valence electrons represented in the models as you move across the periodic table from left to right?
  1. Where do you find the least number of valence electrons – to the left of the periodic table OR to the right of the periodic table? Where do you find the greater number of valence electrons?
  1. Looking at the far right column of models, which elements are modeled? What do you notice about the number of valence electrons which are represented? How does this amount compare to the maximum number possible?
  1. Look at the models of elements that appear in the same period. What do you notice about the number of energy levels when comparing these to each other and to the period they are found in?