Final answer:
Cations are positively charged particles formed when a neutral atom loses electrons, and anions are negatively charged particles formed when a neutral atom gains electrons. Chromogens are compounds that can be converted into pigments with color, and chromophores are the parts responsible for the color.
Step-by-step explanation:
A cation is a positively charged particle that forms when a neutral atom loses one or more electrons from its valence shell. An example of a cation is the sodium cation (Na+). On the other hand, an anion is a negatively charged particle that forms when a neutral atom gains one or more electrons in its valence shell. An example of an anion is the chloride ion (Cl-).
A chromogen is a compound that can be converted into a pigment that absorbs certain wavelengths of light, causing it to have color. A chromophore is the part of the chromogen responsible for the color. For example, in cytochromes, the chromophore is the part of the protein that absorbs light and gives it its characteristic color.