Chemistry I really need help and i will give brainlist please be serious no giving random answers

It is important to wear proper protective equipment in lab even when not actively performing experiments because accidents can affect any researcher, even one not working on an experiment. select the best answer from the choices provided

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.

When balancing a chemical equation: