Here's why:
* Atoms are neutral: Atoms naturally have an equal number of protons (positively charged particles) and electrons (negatively charged particles). This balance results in a neutral charge.
* Adding electrons: When you add an extra electron to an atom, you introduce a negative charge that outweighs the positive charge from the protons. This creates a negative ion.
Example:
* A neutral chlorine atom has 17 protons and 17 electrons.
* If you add one electron to a chlorine atom, it becomes a chloride ion (Cl-) with 17 protons and 18 electrons. The extra electron makes the ion negatively charged.
Note:
* This process is called gaining electrons.
* The opposite process, losing electrons, creates a positive ion (cation).
