Respuesta :

Elements and compounds are considered pure substances.

Answer:  Elements  and Compounds

Explanation:

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. Example: Air

Element is a pure substance which is composed of atoms of similar elements. It can not be decomposed into simpler constituents using chemical reactions.Example: iron [tex](Fe)[/tex]

Solution is a homogeneous mixture of a solute and a solvent. Example: sugar dissolved in water

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: carbon dioxide [tex](CO_2)[/tex]  

Thus Elements  and Compounds are pure substances.