Moles of cacl2 are in 1.25×10,23 atoms

What overall charge must all compounds have

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

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.