A spherical balloon of volume 3.94 103 cm3 contains helium at a pressure of 1.17 105 Pa. How many moles of helium are in the balloon if the average kinetic energy of the helium atoms is 3.60 10-22 J

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.

What are the similarities of physical and chemical change ?

Asolid that forms and separates from a liquid mixture is called