12. A black hole is

A. an object so diffuse that light leaving it is bent totally back to center of the universe.

B. an object so diffuse that light approaching it is blocked from view.

C. an object so dense that light leaving it is bent totally back to the nearest star.

D. an object so dense that light leaving it is bent totally back to the object.

Abird sitting high in a tree is an example of what type of wnergy

Choose the most likely outcome of this scenario: jen decided to go bike riding without a helmet. while no one is around during her ride, she is thrown from her bike when her wheel goes into a pothole. she is not injured, but she is terrified to get back on her bike. what happens next? a. her physical health is affected even though she wasn't hurt. b. her mental and emotional health are affected because she is afraid to get back on her bike. c. her social health is affected because she is worried her friends saw the fall. d. her overall health is not affected at all by her fall.

Aphoton is absorbed by an electron that is in the n = 3 state of a hydrogen atom, causing the hydrogen atom to become ionized. very far away from the nucleus, the released electron has a velocity of 750,000 m/s. what was the wavelength of the absorbed photon?