Answer:
Mixture.
Explanation:
The matter can be classified as:
a) Mixture: Can be homogeneous or heterogeneous.
Mixtures are formed when two or more substances combine and there is no change in the property of the pure substances mixed.
For example:
NaCl and water forms a homogeneous mixture, however on mixing the properties of the two remains the same and they can be separated easily by physical means.
b) Compound: it is formed from two or more elements and this is pure form of matter
c) element: it is the purest form of matter.
Isotopes are the substances which have same atomic number but different atomic mass.
