Question

A solution in a dish contains 4.0 grams of salt dissolved in 100 grams of water. If 50 grams of the water evaporate, this is evidence that the solution is a compound conserving mass an element a mixture

Answer 1

Answer is: a mixture.

Mixtures can be separeted y physical means, while compounds cannot.

Solution is homogeneous mixture composed of two or more substances.  

In aqueous solution, solvent is water and solute (in this example salt) is a substance dissolved in water.

Homogeneous solution of salt and water can be separated with heating (evaporating the water).

Answer 2

Answer: a mixture

Explanation:

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions or physical reactions.Example: Copper $Cu$

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water $H_2O$

Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. It can be decomposed into simpler constituents using physical means. Example: Air