Question

Which of the following best describes the difference between a mixture and a pure substance?
A.
A mixture is made up of only one type of atom; a pure substance is made up of more than one type of atom.
B.
A mixture has different properties throughout; a pure substance has the same properties throughout.
C.
A mixture has the same properties throughout; a pure substance has the different properties throughout.
D.
A mixture is made up of more than one type of atom; a pure substance is made up of only one type of atom.

Answer 1

B

A pure substance has a uniform (definite) composition and the same properties throughout (elements or compounds). A mixture contains two or more substances and can vary in composition and properties throughout (even if a homogeneous mixture appears uniform, its components are not chemically combined).