What property makes an acid considered stronger in relation to ionization?

An acid is considered stronger if it has a greater tendency to donate protons, which is directly related to its ionization in a solution. The strength of an acid is often measured by the extent to which it ionizes or dissociates in water to produce hydrogen ions (H⁺). Strong acids, such as hydrochloric acid (HCl) or sulfuric acid (H₂SO₄), completely dissociate in solution, meaning they readily release protons.

The ability to donate protons is influenced by factors such as the stability of the resulting anion after dissociation. A more stable anion makes it easier for the acid to lose a proton, thereby increasing its strength. In contrast, weaker acids will only partially dissociate in solution and do not have as strong of a tendency to donate protons.

The other options relate to properties that do not accurately define acid strength in terms of ionization. Solubility of salts and the number of carbon atoms in a molecule have little to do with the strength of an acid regarding its ability to donate protons. Similarly, the effectiveness in sharing electrons can apply to a variety of chemical bonds and interactions but is not a primary factor in determining acid strength as it pertains to ionization.