Respuesta :
Answer: a. solution
Explanation:
A solution is a mixture which contains two or more than two types of components and they can be separated by physical means as well.Example: salt water
Molecule of an element is defined as the aggregate of atoms of similar elements. Example: [tex]H_2[/tex]. Molecule of a compound is the aggregate of atoms of different elements in a fixed ratio by mass. Example: [tex]CO_2[/tex]
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: [tex]H_2O[/tex]
A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means. Example: Helium, water
