What is the chemical formula for xylene (theres multiple ones on the internet)?

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.

Why do cells appear different in distilled water than they do in 10% salt water?

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?