1. Express each of the following numbers in scientific notation with the correct number of SF.

How has the scientific community addressed the safety of chemicals? a. chemicals are repeatedly tested, even those that have existed for a long time. b. existing chemicals are tested if they have never been tested before. c. chemicals are tested if they are suspected to have caused a problem. d. only new chemicals are tested.

For each of the following mixtures decide if filtering would be suitable to separate the substances. explain your answers. oil in water sugar in water sand in water chalk in water tea leaves in a cup of tea

Substance x has a fixed volume, and the attraction between its particles is strong .substance y had widely spread out particles and can be compressed what can most likely be concluded about these substances