What is the relationship between halogens and salts?

In Lesson 17-4, we learned that functional groups containing chlorine (Cl) are using the prefix hal(o)-. As a matter of fact, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) are called the halogens or halogen elements collectively.

However, we learned that the suffix hal(o)- meaning sea or salt in Lesson 18-2. Are they using the same prefix? Why is that?

The reason why elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) are called the halogens is because when they react with metals they produce a wide range of salts, including calcium fluoride, sodium chloride (common salt), silver bromide and potassium iodide. Therefore, they are name halogens, meaning 'salt-producing'. The suffix -gen means 'produce', which we learned in Lesson 16-5.

Jöns Jakob Berzelius. Source: Wikipedia

This name was suggested by Swiss chemist Jöns Jakob Berzelius in 1842. However, the term halogen was created by Johann Salomo Christoph Schweigger at 1811. It was suggested for naming chlorine at the time, but it was not used. Later, the term was used by calling all of the element of  group 17 -- including chlorine.

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