Which of the following does not happen during a chemical change? a) mass is gained b) new compounds are formed c) old compounds are broken down d) bonds are broken

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car