Order the theories from oldest to most recent.
1 electrons move about a positively charged nucleus in clouds that are defined by probabilities.
2 atoms are tiny indivisible particles that make up all mater.
3 atoms consist of mostly empty space with a dense nucleus of positive charge. 4 negatively charged electrons are embedded in a mass of positive charge.
5 electrons occupy specific energy levels surrounding a positively charged nucleus.

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.