Help me pls I don’t understand

Consider the balanced equation below. n2h4 + 2h2o2 n2 + 4h2o what are the mole ratios of hydrazine (n2h4) to hydrogen peroxide (h2o2) and hydrazine to water? 1: 2 and 1: 4 1: 3 and 1: 4 1: 2 and 3: 5 1: 3 and 3: 5

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

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.