Practice: Determine the electron arrangement for the Cl– ion.
The Octet Rule states that main-group elements will generally form enough bonds to obtain 8 electrons in their valence shell.
Concept #1: Octet Rule
Example #1: How many electrons must the sodium atom (Z =11) lose in order to obtain a filled outer shell?
Example #2: Write the electron arrangement for the following ion: Ca2+ (Z = 20)
For a metal cation, first remove electrons from the highest energy level.
Example #3: Write the electron arrangement for the following ion: N3– (Z = 7)
For a non-metal anion, add electrons to the orbital with available space.
Practice: Determine the electron arrangement for the Cl– ion.
Practice: Determine the electron arrangement for the Al3+ ion.
