Using the periodic table, determine the position of each pair of specified atoms.
 1. Determine the total number of valence electrons for each element.
 2. Provide the total number of core electrons for each element.

a. Sodium and potassium

b. Boron and aluminium

• A. a. 1. Sodium and potassium both have 2 valence electrons,
  2. Sodium has 10 core electrons and potassium has 18 core electrons,
  b. 1. Boron and aluminum both have 4 valence electrons,
  2. Boron has 2 core electrons and aluminum has 10 core electrons.
• B. a. 1. Sodium and potassium both have 1 valence electron,
  2. Sodium has 11 core electrons and Potassium has 19 core electrons,
  b. 1. Boron and aluminum both have 3 valence electrons,
  2. Boron has 2 core electrons and aluminum has 10 core electrons.
• C. a. 1. Sodium and potassium both have 1 valence electron,
  2. Sodium has 10 core electrons and Potassium has 18 core electrons,
  b. 1. Boron and aluminum both have 3 valence electrons,
  2. Boron has 5 core electrons and aluminum has 13 core electrons.
• D. a. 1. Sodium and potassium both have 1 valence electron,
  2. Sodium has 10 core electrons and potassium has 18 core electrons,
  b. 1. Boron and aluminum both have 3 valence electrons,
  2. Boron has 2 core electrons and aluminum has 10 core electrons.

Answer: (D)