Question

Identify the following substances as pure substances, elements, compounds, mixtures,
or solutions (answers may include more than one classification): mud, copper, salt
water, carbon monoxide

Answer 1

I'm not a science teacher -- and remember very little from my science classes 65 years ago.

I suggest you google each of those.

Answer 2

copper. Element. Pure substance.
salt. I assume you mean table salt but there are many salts. It is pure if it is 100% salt, NaCl. It is a compound.
Water is a compound. It is a pure substance.
Carbon monoxide is a compound and a pure substance.
Mud is a mixture. Some parts of the mud are in solution.
The word "pure" can be a little misleading. I consider something as pure if it is 100%; table salt is pure in my opinion if it is 100% salt but it isn't pure in the sense that it is partly sodium and partly chlorine. However, it IS a pure substance in that there is nothing mixed with it. By the way, most table salt one buys at the store has been "iodized" which makes it a mixture. One CAN buy un-iodized salt and that is a pure compound.