Question

1 which of the following is a key characteristic of an acid - base reaction?
options:
formation of a solid precipitate
transfer of protons (h+ ions)
change in oxidation numbers
production of metal crystals

Explanation:

Acid-base reactions (per Brønsted-Lowry theory) center on the transfer of protons ($\text{H}^+$ ions). Formation of a precipitate is a double displacement reaction characteristic, oxidation number changes occur in redox reactions, and metal crystal production is unrelated to acid-base chemistry.

Answer:

Transfer of protons (H+ ions)