The strength of an acid or base is determined by its ability to donate or accept protons (H+ ions). Strong acids and bases completely dissociate in water, releasing all of their protons or hydroxide ions (OH-). Weak acids and bases only partially dissociate, meaning that only a small fraction of their molecules release protons or hydroxide ions.

The strength of an acid is measured by its acid dissociation constant (Ka). The Ka is the equilibrium constant for the dissociation of an acid in water. The higher the Ka, the stronger the acid.

The strength of a base is measured by its base dissociation constant (Kb). The Kb is the equilibrium constant for the dissociation of a base in water. The higher the Kb, the stronger the base.

Strong acids and bases have Ka and Kb values that are much greater than 1, while weak acids and bases have Ka and Kb values that are much less than 1.

Here is a table summarizing the properties of strong and weak acids and bases:

| Property | Strong Acid | Weak Acid | Strong Base | Weak Base |

|---|---|---|---|---|

| Dissociation | Completely dissociates in water | Partially dissociates in water | Completely dissociates in water | Partially dissociates in water |

| Ka | Ka >> 1 | Ka << 1 | Kb >> 1 | Kb << 1 |

| pH | pH < 7 | pH > 7 | pH > 7 | pH < 7 |

| Examples | HCl, H2SO4, HNO3 | CH3COOH, H2CO3, HF | NaOH, KOH, Ca(OH)2 | NH3, CH3NH2, pyridine |

Strong acids and bases are typically corrosive and can cause severe burns. Weak acids and bases are generally less harmful, but they can still cause irritation.