Understanding the Valency of Sodium Chloride (NaCl)
Sodium chloride, commonly known as table salt (NaCl), is a compound formed by the combination of two elements: sodium (Na) and chlorine (Cl). The valency of NaCl can be comprehended by examining the valencies of its constituent elements. This article explains the valency of NaCl and the reasons behind its stability.
Valencies of Sodium and Chlorine
Sodium (Na) has a valency of 1 due to its tendency to lose one electron to achieve a stable electronic configuration. Sodium's electronic configuration is 1s2 2s2 2p6 3s1. By losing this single electron, it attains the stable electron configuration of neon (Ne), which is the nearest noble gas in the periodic table.
Chlorine (Cl), on the other hand, has a valency of -1 as it tends to gain one electron to complete its outer shell. Chlorine's atomic number is 17, and its electronic configuration is 1s2 2s2 2p6 3s2 3p5. By gaining one electron, chlorine achieves the stable electron configuration of argon (Ar), the nearest noble gas.
The Formation of NaCl
In NaCl, one sodium ion (Na ) combines with one chloride ion (Cl-). The overall valency of NaCl is considered to be neutral because the positive and negative charges of the compound are balanced. This balance is crucial for the compound's stability and the formation of ionic bonds.
Why Sodium Has a Valency of 1 and Chlorine Has a Valency of -1
Sodium's high ionization energy (the energy required to remove an electron from sodium) means that it can only lose one electron to achieve stability. The second ionization energy is much higher, requiring an even greater amount of energy to remove the second electron. Therefore, sodium is limited to a valency of 1.
Chlorine, with its tendency to gain one electron, has a valency of -1 because it needs just one electron to complete its outer shell and achieve a stable octet configuration. The stability provided by a complete valence shell is significant, as it makes the compound more stable and less reactive.
Conclusion
The valency of sodium chloride (NaCl) is determined by the valencies of its component elements, sodium (1) and chlorine (-1). The combination of these elements results in a stable compound with a neutral overall charge. Understanding the valency and the principles behind the formation of NaCl is essential for comprehending the nature of ionic compounds and their properties.