What is a substance? A. a uniform mixture that can't be separated
В. a mixture that can be separated
С. a single component that can't be separated
D. a single component that can be separated

С. a single component that can't be separated

Explanation:

Substance : It is the pure form of matter or we can say that it is a matter that contains only one type of molecule of atom. It can not be separated by physical process.

For example : Water is a substance.

Mixture : It is a combination of different type of atoms or molecules and it is an impure form.

For example : Sodium chloride with water is a mixture.

Hence, the correct option is, (C) a single component that can’t be separated.

C. A single component

Explanation:

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measure their densities same density, same sub