What characterizes a mixture?

A mixture is characterized by the combination of two or more different elements or compounds that are physically blended together without undergoing a chemical reaction. This means that while the individual components retain their own properties and identities, they are combined to create a new material that can exhibit a range of characteristics derived from the original substances.

For example, when sand is mixed with salt, both substances retain their original properties: the sand remains gritty and the salt remains salty. This differentiates a mixture from a compound, where elements chemically bond to form a substance with distinct properties that differ from those of the individual elements.

Furthermore, in a mixture, the ratio of the components can vary, allowing for a wide array of possible mixtures with varying properties. This flexibility is a key characteristic of mixtures, making them fundamentally different from the fixed compositions found in pure substances or chemical compounds.

In contrast, options that suggest a singular substance or unchanging combinations do not reflect the variable nature of mixtures, while implying a chemical reaction to create new substances is indicative of a compound rather than a mixture.