The chemical composition of the gases surrounding the earth has changed substantially over the past 4 billion years. one notable change was due to the emergence of photosynthetic organisms. the process of photosynthesis increased the amount of what gas in the atmosphere?

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

If two atoms are bonded to a central atom with no lone pairs,how will they be arranged

Fred is studying a substance that is made out of only one element. this means that