24 !
unstable potassium oxide reacts with water vapor in the air to produce potassium hydroxide:
k2o + h2o → koh
what, if anything, should be done to balance this chemical equation?
a. nothing. it is balanced.
b. put a "2" in front of the koh.
c. put a "4" in front of the koh.
d. put ".5" in front of both k2o and h2o.

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.