What are halogens classified as?

Halogens are indeed classified as non-metals found in Group 7 of the periodic table. They are characterized by their unique properties, including the presence of coloured vapours. For example, chlorine appears yellow-green, bromine is reddish-brown, and iodine possesses a violet vapour when heated.

The classification as non-metals is significant because halogens generally exhibit high electronegativity and tendency to gain electrons during chemical reactions, forming negative ions (anions). This is a key aspect of their reactivity. Being in Group 7 also indicates that they have seven electrons in their outer shell, striving to achieve a stable octet configuration by gaining one additional electron.

Other classifications do not accurately reflect the properties of halogens, hence they do not fit. The designation of halogens as metals, or as metalloids, is inaccurate due to their non-metallic nature and they do not belong to Group 1, which consists of alkali metals that have very different properties. Thus, the selection of non-metals in Group 7 with coloured vapours encapsulates the essential characteristics of halogens correctly.