Sodium, lithium and potassium all show similar properties. explain how this is possible

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.

Balance this equation co2(g) + h2o (g) show that the balanced equation obeys the law if conversation of mass

Which of the following units is not an official si unit