A ball is dropped from the top of a building. When does the ball have the most kinetic energy? A. as it is released B. after it has hit the ground C. half way through the fall D. just before it hits the ground

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Butadiene undergoes a reaction at a certain temperature in the gas phase as follows: 2c4h6(g) --> c8h12(g) the following data were collected for this reaction: time (min) [c4h6] (m) 0 0.36 15 0.30 30 0.25 48 0.19 75 0. determine the order of the reaction and the rate constant. 1st order and k = 4.3x10 -4 s-1 1st order and k = 2.3x10-4 s-1 2nd order and k = 4.3x10-4 s-1 2nd order and k = 2.3x10-4 s-1 zero and k = 4.3x10-4 s-1