The ph of a solution is 4.8, what is the concentration of hydroxide ion in the solution ​

There are main groups in the modern periodic table of elements

In the following redox reaction which is the oxidizing agent and which is the reducing agent? alcl3 + na nacl + al

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.