* Atom: An atom is electrically neutral, meaning it has an equal number of protons (positively charged particles) and electrons (negatively charged particles).
* Ion: An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a net positive or negative charge.
Here's a breakdown:
* Cations: Positively charged ions formed when an atom loses electrons.
* Anions: Negatively charged ions formed when an atom gains electrons.
Example:
* Sodium atom (Na): Contains 11 protons and 11 electrons, giving it a neutral charge.
* Sodium ion (Na+): When a sodium atom loses one electron, it becomes a sodium ion with 11 protons and 10 electrons, resulting in a net positive charge of +1.
Important Note: While the charge is the primary structural difference, the loss or gain of electrons can also slightly affect the size of an ion compared to its parent atom.
* Cations are generally smaller than their corresponding atoms because they have fewer electrons and a stronger attraction between the remaining electrons and the nucleus.
* Anions are generally larger than their corresponding atoms because the addition of electrons increases the electron-electron repulsion, making the electron cloud larger.
