What's an element in period 5 with larger radius than yttrium?

Different isotopes indicate that an element will have different numbers of

What does the process of natural selection involve

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.