Final answer:
Halogens all form ions with a -1 charge when they form ionic compounds with metals, a statement which is true. While most halides of metals are ionic, certain metals form covalent halides. The -1 charge of halogens is due to their tendency to gain one electron to achieve a stable electron configuration.
Step-by-step explanation:
The statement that halogens all form ions with a charge in their ionic compounds with metals is true. Halogens, being in the second-to-last column of the periodic table, have seven valence electrons and thus tend to gain one electron to achieve a stable octet configuration, much like the noble gases. This gain of an electron results in a singly negative ion with a charge of -1, forming ionic bonds with metals.
Halogens form halides with metals, and these halides can vary from being ionic to covalent. Most binary halides are ionic, especially with metals not including mercury, group 13 elements with a 3+ oxidation state, tin(IV), and lead(IV), which form covalent binary halides. While ionic halides often occur with alkali and alkaline earth metals, which themselves form +1 and +2 cations, respectively, the halogen anions balance this by forming -1 anions.
Additionally, the reactivity of the halogens and the tendency to form negative ions is evidenced by the formation of interhalogens and polyhalides. Interhalogens are compounds composed of two or more different halogens, while polyhalides often involve an alkali metal and a halogen, resulting in anions composed of at least three halogen atoms.