Which element is used in light bulbs as filament

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

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.

12. calculate the hydroxide ion concentration of a solution with ph = 3.25. show all calculations leading to an answer