1. Write the electron configurations for Li, Na and K. (Remember for electron configurations, arrows are not necessary.)
  2. What is similar about the electron configurations of all of the elements in question 1? Look at the very end of their configurations.Lithium (Li) is in row 2 of the periodic table, sodium (Na) is in row 3, and potassium is in row 4. How do their row numbers affect how their electron configurations end?
  3. Write the electron configurations for Be, Mg, and Ca.
  4. Name the element that have an electron configuration ending with… (the first is done for you)

a) 5s1 _Rubidium (Rb)__b) 6s2 ______c) 7s1 ______

  1. Write the electron configurations for B, Al, and Ga and note their similarities.
  2. Write the electron configurations for N, P and As and note their similarities.
  3. Write the electron configurations for Ti, Zr, and Hf and note their similarities.
  4. Write the electron configurations for Cr, Mo, and W and note what is similar about them.
  5. Name the elements that have an electron configuration ending with…(the first is done for you)

a) 4d3 _Niobium (Nb)_b) 5d8 __c) 3d6 _

Write both the full electron configuration for each of the following and orbital notation

1. Beryllium :______

2. Nitrogen :______

3. Potassium :______

4. Manganese :______

5. Tin :______

6. Tunsten :______

II. Identify the element for each of the following electron configurations:

1. 1s22s22p6:______

2. 1s22s22p63s23p64s23d9:______

3. 1s22s22p63s23p64s23d104p65s24d105p5:______

4. 1s22s22p63s23p64s23d104p65s24d105p66s24f10:______

III. Determine whether the following electron configurations are valid or invalid, and if invalid, correct it.

1.1s22s22p23s2:______

2.1s22s22p63s23p63d1:______

3.1s22s22p63s23p64s23d104p65s24d105p6:______

Critical Thinking Questions for Electron Configurations

  1. How many sublevels exist in the 1st energy level?
  2. How many sublevels exist in the 2nd energy level?
  3. How many sublevels exist in the 3rd energy level?
  4. Does the 3f sublevel exist? Explain
  5. How many orbitals are there in a p sublevel?
  6. How many orbitals are there in a d sublevel?
  7. In your own words what is the difference between a sublevel and an orbital?
  8. How many electrons can fit in each of the following energy levels: 1st energy level, 2nd energy level, 3rd energy level, 4th energy level?

Example 1: 3p ______

Example 2 : 4d ______

Questions:

9. In example # 2 why are there 5 lines drawn next to the d?

10. In example # 1 why are there 3 lines drawn next to the p?

  1. What does the number 3 and 4 represent for each example?
  1. What is wrong with the following notation? 2d ______You should find two things wrong.
  2. How many unpaired electrons are in a nitrogen atom?
  3. Why does carbon’s sixth electron have to go into another p orbital? Why can’t it go into a 2s orbital? Why can’t it go into a 3s orbital?
  4. How many unpaired electrons are in sulfur atom? What did you need to answer this question?