Anew concept that is tested in a scientific investigation is known as

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.

How do i turn 2 s into one in the products

To calculate percent by mass, use the equation below: calculate the percent by mass of each element. %n = % %h = % %o = %