This is the third most abundant gas in the atmosphere this is from a crossword puzzle and it has 5 letters.

c.the charges if the proton and electron and gravity

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.