Directions: Study the table and box below. The two gives you an idea of what makes a set of quantum numbers ALLOWED or VALID. Take note that I presented arrows to you to visualize the spin of each electron and how they occupy orbitals. Have you noticed any pattern in placing the arrows inside the boxes? Well, it is governed by Hund’s Rule which states that each orbital should be filled in individually before doubling it. Do you get what I mean? Let me provide you an example. Let us take the case of an Oxygen atom: 1 2 2 2 2 4 : CORRECT INCORRECT Chemi cal Symbol Electron Configurat ion Orbital Diagram 1H 1 1 2He 1 2 3Li 1 2 2 1 4Be 1 2 2 2 5B 1 2 2 2 2 1 6C 1 2 2 2 2 2 7N 1 2 2 2 2 3 8O 1 2 2 2 2 4 9F 1 2 2 2 2 5 10Ne 1 2 2 2 2 6 Orbitals: s = 2e- p = 6e- d = 10e- f = 14eSpin: = + 1 2 (clockwise) = − 1 2 (counterclockwise) Element: Carbon Atomic No.: 6 No. of e-: 6 e- configuration:1 2 2 2 2 2 1st e-: = 1; = 0; = 0; = + 1 2 2nd e-: = 1; = 0; = 0; = − 1 2 3rd e-: = 2; = 0; = 0; = + 1 2 4th e-: = 2; = 0; = 0; = − 1 2 5th e-: = 2; = 1; = −1; = + 1 2 6