Which of the following solution is a buffer? a solution containing hf and naoh, nh3 and nh4+, hcn and hno3?

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.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium

At element makes up all organic compounds?