Sodium Atom (Na)
* Electron Configuration: 1s² 2s² 2p⁶ 3s¹
* Valence Electrons: 1 (the lone electron in the 3s orbital)
Sodium Ion (Na+)
* Electron Configuration: 1s² 2s² 2p⁶
* Valence Electrons: 0
The Change
When a sodium atom becomes a sodium ion (Na+), it loses its single valence electron. This electron is donated to another atom, typically a nonmetal, to form an ionic bond. The loss of this electron leaves the sodium ion with a full outer shell (the 2p shell), making it more stable.
Key Points
* Stability: Ions are more stable than their corresponding neutral atoms because they have a full outer shell of electrons.
* Charge: Losing an electron gives the sodium ion a positive charge (+1), as there are now more protons than electrons.
* Octet Rule: Sodium, by losing its electron, achieves a stable electron configuration like the noble gas neon (Ne), fulfilling the octet rule.
