Question

etching is a process for producing images on metal plates that can be copied using a printing press. first, the metal plate is coated in a layer of wax. next, an artist creates the image by scratching lines in the wax to reveal the metal. finally, the plate is dipped in a liquid called the mordant, which eats away at the metal where the wax has been scraped away. this leaves an engraving in the plate that can pick up ink for printing. to break down the metal plate, the mordant should be composed of a(n) substance.

Explanation:

The mordant needs to chemically break down (corrode) metal. Substances that react with and dissolve/erode metals are acidic, as acids react with most metals to produce metal salts and hydrogen gas, which would eat away at the exposed metal in the etching process.

Answer:

acidic