Definition: The term "chalcogen" refers to a group of elements that are found in the element table of the periodic table. These elements are commonly known as halogens, which include chlorine (Cl), bromine (Br), iodine (I), and neon (Ne). Halogens have the chemical formula Cl, Br, I, or Ne, respectively, with electronegativity values ranging from -1 to +3, indicating how strongly their valence electrons are attracted to other atoms.