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.

The answer is acidic  

Explanation:

because did the test

acidic

Explanation:

3.2x10^7

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.