When ionic compounds are added to water, they dissociate or break apart into ions. In the case of table salt, salt added to water dissociates into sodium ions and chloride ions. This would seem to be a chemical change. However, scientists do not consider this to be one, because the solid table salt remains after the water is evaporated. The atoms recombine into their original arrangement once the water is removed.
Which word from the selection helps you understand that physical changes can be undone?
a added
b dissociate
c recombine.
d removed