What characterizes a mixture?

A mixture is characterized as a physical blend of two or more components. This means that the substances within the mixture retain their individual properties and identities. Unlike pure substances, which have a uniform composition and distinct set of properties, mixtures can vary in composition and can be separated into their individual components through physical methods, such as filtration, distillation, or centrifugation.

This understanding is critical because it highlights that the components in a mixture do not undergo any chemical change during the blending process. For instance, when salt is mixed with sand, both substances maintain their own properties; salt remains salty, and sand remains sandy. This is in contrast to pure substances where a specific chemical formula defines their identity.

In a mixture, the ratios of components can vary, leading to different properties in different samples of the same mixture. This is an essential distinction in chemistry and underlines why option B accurately captures the essence of what makes up a mixture.