Who created the first compound microscope and telescope?

What is the mass of 4 molecules of co2

Find the mass in grams of 1.37x1020 particles of h3po4

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.