Which term describes a substance made of one type of particle?

Which term describes a substance made of one type of particle?

• A. Pure substance
• B. Element
• C. Mixture
• D. Solution

Answer: (A)

A substance with a fixed, uniform composition is a pure substance. This means every particle in the material is the same kind, so the sample has consistent properties throughout. Pure substances include elements (made of one type of atom) and compounds (molecules with a specific combination of atoms). Mixtures lack uniform composition because they contain two or more different substances physically joined; a solution is a homogeneous mixture, which is still a mixture but evenly distributed. Since the question describes a substance made of one type of particle, the term that fits best is pure substance.

A substance with a fixed, uniform composition is a pure substance. This means every particle in the material is the same kind, so the sample has consistent properties throughout. Pure substances include elements (made of one type of atom) and compounds (molecules with a specific combination of atoms). Mixtures lack uniform composition because they contain two or more different substances physically joined; a solution is a homogeneous mixture, which is still a mixture but evenly distributed. Since the question describes a substance made of one type of particle, the term that fits best is pure substance.