What is a key characteristic of halogen gases?

Halogen gases are known for their ability to form salts, particularly when they react with metals. This process involves the transfer of electrons from a metal atom to a halogen atom, leading to the formation of ionic compounds, commonly referred to as salts. For instance, when sodium, a metal, reacts with chlorine, a halogen, it forms sodium chloride (table salt). This salt formation is a fundamental characteristic of halogens, demonstrating their reactivity and the way they engage in chemical reactions with metals.

Understanding this characteristic illustrates the nature of halogens: despite being nonmetals, they readily interact with metals to create stable compounds. The ability to form salts is a defining feature of halogens, which is why this aspect is critical for identifying and studying their behavior in chemistry.