Aroller coaster reaches its maximum potential energy when it

a. is sitting at the top of a hill.
b. reaches the bottom of a hill.
c. rounds a curve.
d. starts up a hill.

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.

Some animals that try to adapt to climate changes eventually die due to starvation, as climate change alters the web.

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as