Given a scientific passage and an answer, generate a question for the given answer.

Example input: Passage: A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:. Answer: nucleotides.
Example output: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Example explanation: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.
Q: Passage: By gaining an electron, the chlorine atom becomes a chloride ion. It now has more electrons than protons and a charge of -1. Negative ions are named by adding the suffix ide to the first part of the element name. The symbol for chloride is Cl - . Answer: negative ions
A:
What kind of ions are named by adding the suffix -ide to the end?