Why is this principle about the relationship between mass and volume always true of substances, but not always true of mixtures?

Which of these best describes an ionic bond?

Explain how the integumentary system plays a crucial role in the ability to maintain homeoestasis

Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage