Labster Theory: Cations

Definition of a Cation: A cation (pronounced cat-ion) is defined as a positively charged ion.
Origin of Positive Charge: The positive charge of a cation is a direct result of an atom losing one or more electrons. Because electrons carry a negative charge, their removal leaves the atom with more protons than electrons, resulting in a net positive charge.

The Potassium Atom ( $K$ ):
- Nuclear Composition: The nucleus contains $19$ protons and $20$ neutrons.
- Electron Count: An uncharged potassium atom has $19$ electrons.
- Net Charge: Because the number of protons ( $+19$ ) is equal to the number of electrons ( $-19$ ), the atom is electrically neutral.
The Potassium Cation ( $K^+$ ):
- Nuclear Composition: The nucleus remains unchanged, containing $19$ protons and $20$ neutrons.
- Electron Loss: Through the process of ionization, the potassium atom loses one electron.
- Revised Electron Count: The resulting cation has $18$ electrons.
- Charge Calculation: The overall charge is determined by the difference between the number of protons and electrons:
  - $19 \text{ protons} - 18 \text{ electrons} = +1 \text{ overall charge}$

Superscript Notation: The charge of an ion is explicitly indicated using a superscript following the element symbol (e.g., $K^+$ ).
Structural Comparison (Figure 1):
- $K$ Atom: Characterized by an equal balance of protons and electrons ( $19$ each).
- $K^+$ Ion: Characterized by a deficit of one electron relative to its proton count, resulting in the $+1$ charge.
- Consistency of Nucleus: It is important to note that during the formation of a cation, the number of protons and neutrons in the nucleus (the atomic number and mass number) does not change; only the electron cloud is affected.