Answer:
<u>Answer D. Scratching it with other materials</u>
Explanation:
Let's start eliminating some answers
Answer A; If you hit an object with a hammer, you will just figure out if that object can be broken with a certain amount of force. In most cases, this will not be helpful.
Answer B; When putting a material in an acid, many things could happen. This things that happen are called chemical reactions. Not every material will have a chemical reaction so this step could be useless.
Answer C; Chipping a piece off of a material will not grant you much information. Yes if may be easier to experiment will a smaller piece but the action by it's self is not useful.
Answer D; Scratching a material will another material can be very helpful. If you have two materials, labeled A and B, you can find out the Mohs hardness scale. If A is damaged by B, the hardness of A is less than B and vise versa. This can be very helpful when identifying materials.
So answer D makes the most sense
