What is the primary difference between a new substance being formed, like rust, and a mixture being created?

A new substance involves a chemical bond, while a mixture is a physical blend.

A mixture always results in a substance that has a higher density than its original parts.

A new substance can always be easily separated back into its original components, unlike a mixture.

Creating a mixture requires a significant input of energy, like heat or electricity.

A chef makes a salad dressing by shaking oil, vinegar, and herbs together. After a few minutes, the oil and vinegar separate into layers. What does this separation demonstrate about the salad dressing?

That a new, permanent substance was created when the ingredients were shaken.

That the dressing is a mixture whose components can be physically separated.

That the oil and vinegar are chemically bonded together into a single liquid.

That the herbs have dissolved to form a new chemical compound with the oil.

They chemically react to form a new substance with different properties.

They are physically blended together but each keeps its own original properties.

They can only be separated from each other using chemical reactions.

They must all be in the same state of matter (solid, liquid, or gas).

A bowl of salad with lettuce and tomatoes