What is the correct name for the compound nh4clo4?

As you move from right to left on the periodic table the atomic radius fill in the blank

4. absorption has the highest risk of overdose due to increased potency. a. rectal b. oral c. transdermal d. intranasal

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.