Astronomers believe some stars are moving away from earth by measuring the extent to which their light is “stretched” into the red part of the color spectrum, representing the lower frequencies on that spectrum.
In short, stars moving away from earth are “red-shift”, while if they were moving towards the earth they would take on a “blue-shift”.
Answer:
Isotopes can both be the same element but have a different number of electrons
Explanation: not sure if more was supposed to be there, but i tried
The answer is B because the water molecules
