Which two events are independent? a and x a and y b and x b and y

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

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.