Get the definitions of cations and anions. See examples of the two types of ions, learn how they are different, and see periodic table trends.
Explore the differences between cations and anions, their roles in chemical reactions, and their placement on the periodic table. Learn more now.
A cation is a positively charged ion with fewer electrons than protons [2] (e.g. K + (potassium ion)) while an anion is a negatively charged ion with more electrons than protons [3] (e.g. Cl − (chloride ion) and OH − (hydroxide ion)).
An anion is an ion that is negatively charged, and is attracted to the anode (positive electrode) in electrolysis. A cation has a net positive charge, and is attracted to the cathode (negative electrode) during electrolysis.
🧪 Cations vs. Anions: What’s the Difference? (With Simple Examples!) TL;DR: Cations are positively charged ions (like Na+), while anions are negatively charged ions (like Cl-). They form when atoms gain or lose electrons, and they’re everywhere—from table salt to your body’s chemistry! This guide breaks down their differences, real-world examples, and how they interact. —
Whether an atom forms a cation or an anion depends on its position on the periodic table. Group 1A and 2A of the periodic table, alkali metals and alkaline earth metals respectively, always form cations. In contrast, Group 17A, which consists of halogens, always forms anions.
Anions are highly reactive in the gaseous state and will react with cations to generate neutral molecules. Anions, on the other hand, can exist in both liquid and solid states.
Cations and anions are both ions, but they differ based on their net electrical charge; cations are positive, while anions are negative.