Describe what happened to the colored water and the pieces of paper after the holes were punched in the material covering the beaker.

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.

What semimetal can form four single covalent bonds.

Which statement is best described as a atom