A Change for the Better

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One of the fascinating things about chemistry is the way in which the chemical elements drastically change their behaviour when they combine to make new substances.

Ordinary table salt, or sodium chloride, can be made from the green gas, chlorine, and the silvery metal, sodium. Because sodium and chlorine are so reactive, we don’t find them in their free uncombined state in nature. However, we can extract them from substances like salt.

Furthermore, because of their reactivity, they can be highly dangerous. A piece of sodium the size of a pea can ignite if it comes into contact with water. Chlorine was one of the poisonous gases used in World War 1. Chlorine and sodium are quite hazardous on their own but become benign when combined into table salt. They completely change their form and properties in this substance.

The explanation for this dramatic change in sodium and chlorine stems largely from the profound difference one little electron makes. When sodium chloride forms, every atom of sodium that reacts with chlorine gives an electron to a chlorine atom. This electron exchange changes the neutral atoms into oppositely charged ions, which attract each other so strongly they form stable salt. It’s certainly a change for the better.

So next time you sprinkle salt on your fish and chips, be thankful for the difference that moving one electron can make.