when dissolved in water, an acid or a base breaks down into a. a proton and an electron b. two negative ions c. a positive and a negative ion d. a positive ion and a proton

C. A positive and a negative ion

Explanation:

Acids and bases are made up of charged particles known as ions. The ions present in acids are oppositely charged and are held together by strong electrostatic forces. When acids or bases are dissolved in water, the electrostatic forces holding their individual molecules together are weakened and these ions are free to move apart in a process known as dissociation. Dissociation occurs because of the attraction between the positive and negative ions in the acid and bases and the negative and positive polarity of water.

For example, when an acid like hydrochloric acid is dissolved in water it dissociates into positive and negative ions as follows:

HCl(aq) > H+ + Cl-

When a base like sodium hydroxide is dissolved in water, it dissociates into positive and negative ions as follows:

NaOH(aq) > Na+ + OH-