Why is the metric system the preferred system of measurement for science?

The formation of a solid, also known as a is an indication of a chemical change. precipitate particulate particle powder

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.

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.