Question

One difference between mixtures and pure substances is that A) mixtures can be physically separated. B) mixtures are made of one type of atom. C) pure substances have no chemical bonds. D) pure substances can be physically separated.

Answer 1

Answer:

A

Explanation:

Pure substances are substances made of only one compound, and mixtures, substances made of two or more compounds. To separate the compounds of a mixture, it can be used chemical or physical separation. For example, to separate sand and water it may be used as a filter, which is a physical separation. But if there are small particles in the water, maybe it would be necessary coagulation with some chemical element before a filtration, which would be a chemical separation.

To separate the elements of a pure substance, only chemical separations can be used: would be necessary a chemical reaction to form H2 and O2 from H20, for example. So, letter A is correct.

Letter B is incorrect because can be differents atoms in the mixture, depends on its components.

Letter C is incorrect because all molecules, compounds, and substances have chemical bonds, it's the force that let the elements be together.

Letter D is incorrect because, as explained, pure substances only can be separated in their elements by a chemical reaction.

Answer 2

If I'm not wrong I would say C