What percentage do the elements hydrogen and helium account for in the universe? a. 100% b. 99.9% c. 98% d.99.8%

3) in peaches, [oh]=3.16x10-11 m a) find [h+ ] b) what is the ph? c) is the solution acidic, basic, or neutral?

Which of the following are good traits of a hypothesis? it will be able to be testedit can predict an outcomeit will explain the observationsall of these

Scientists have developed an explanation of a phenomenon from several verified hypotheses. the explanation has been confirmed through numerous experimental tests.which option best describes this explanation? a. scientific lawb. research questionc. hypothesisd. scientific theory