* Sodium (Na) has a single valence electron, meaning it only needs to lose one electron to achieve a stable, full outer shell like the noble gases.
* Chlorine (Cl) has seven valence electrons, and needs to gain one electron to achieve a stable, full outer shell.
Here's how the reaction happens:
1. Sodium readily loses its valence electron, becoming a positively charged sodium ion (Na+). This is because it requires less energy to lose one electron than to gain seven.
2. Chlorine readily gains an electron, becoming a negatively charged chloride ion (Cl-). This is because it's energetically favorable to fill its outer shell.
3. The oppositely charged ions are strongly attracted to each other due to electrostatic forces, forming an ionic bond. This bond creates a stable compound, sodium chloride (NaCl), also known as table salt.
Key points:
* Low ionization energy of sodium: Sodium easily loses its electron due to its low ionization energy.
* High electron affinity of chlorine: Chlorine readily gains an electron due to its high electron affinity.
* Strong ionic bond: The resulting ionic bond between sodium and chlorine is very strong, contributing to the high reactivity of the reaction.
This combination of factors makes the reaction between sodium and chlorine highly exothermic (releasing energy), leading to a vigorous and often explosive reaction.
