What would you react with an aldehyde to form a carboxylic acid, that does not react with an alcohol?

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.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm