Mr.Q 發問時間: Science & MathematicsChemistry · 9 年前

How many valence electrons are there?

How many valence electrons are there in an atom with the electron configuration [noble gas]ns2(n-1)d8 ?

(A) 2 (B) 6 (C) 8 (D) 10 (E) 18

The answer is (D)

WHY? Please explain.

1 個解答

  • 9 年前

    Lets say its 4s2 3d8. An atom always tries to get stable by completing its orbital. Hence the 2 electrons in 4s is given to the 3d orbital to complete its quota of 10 electrons. Hence the hybrid configuration is 4s0 3d10.