What is an aquifer. e

What is the h+ concentration for an aqueous solution with poh = 4.01 at 25 ∘c? express your answer to two significant figures and include the appropriate units.

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

What was bohr’s contribution to the planetary model