Which statement best describes a mixture?

Which statement best describes a mixture?

• A. A pure substance with fixed composition
• B. A substance formed by chemical bonds
• C. A solution with dissolved solute
• D. Two or more pure substances that are combined physically but not chemically

Answer: (D)

Mixtures are made when two or more substances are physically combined, not chemically bound to one another. Because there isn't new chemical bonding, each component keeps its own properties and can often be separated by physical methods such as filtration, distillation, or magnetic separation. This allows mixtures to have a wide range of compositions and appearances, including both homogeneous mixtures (like a salt solution) and heterogeneous ones (like sand and iron filings). The statement that best captures this idea is that two or more pure substances are combined physically but not chemically, because it describes the general case of what a mixture is. A pure substance describes a single material with fixed composition, which is not a mixture. A substance formed by chemical bonds refers to a compound, which is chemically bonded and not a mixture. A solution is a specific type of mixture, namely a homogeneous one with a dissolved solute, but not all mixtures are solutions.

Mixtures are made when two or more substances are physically combined, not chemically bound to one another. Because there isn't new chemical bonding, each component keeps its own properties and can often be separated by physical methods such as filtration, distillation, or magnetic separation. This allows mixtures to have a wide range of compositions and appearances, including both homogeneous mixtures (like a salt solution) and heterogeneous ones (like sand and iron filings).

The statement that best captures this idea is that two or more pure substances are combined physically but not chemically, because it describes the general case of what a mixture is. A pure substance describes a single material with fixed composition, which is not a mixture. A substance formed by chemical bonds refers to a compound, which is chemically bonded and not a mixture. A solution is a specific type of mixture, namely a homogeneous one with a dissolved solute, but not all mixtures are solutions.