Final answer:
Chlorine can be replaced by other halogens such as fluorine, bromine, iodine, and astatine as potential substitutes.
Step-by-step explanation:
The element chlorine, which is a halogen, can be replaced by other halogens as potential substitutes. These halogens include fluorine, bromine, iodine, and astatine. However, it is important to note that the reactivity of these elements should be considered when choosing a replacement.