If a skater has 2000 J of GPE at the top of a skate ramp, how much ME does the skater have? How much KE will they have a the bottom of the ramp?

Ihave this 50 question test the layer of earth's atmosphere where atoms and molecules escape into space is referred to as the a) exosphere b) ionosphere. c) mesosphere d) thermosphere

Which change would make the diagram correct?

Definition: this is the weighted average of all of the isotopes of an element.