Cells in the human eye send nerve impulse to the brain that cause the pupil to constrict. this i a an example of a reaction to what kind of stimuli?
a. light
b. touch
c. chemicals
d. sound

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.