An electron in a hydrogen atom moves from level 3 to level 1. in a second hydrogen atom, an electron drops from level 2 to level 1. which statement describes the most likely result?
the first atom emits light with more energy.
the second atom emits light with more energy.
the first and second atoms absorb energy without emitting light.
the first and second atoms emit light with the same amount of energy.

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Compare the equilibrium constants for the systems shown in the table. which favors products the most? which favors products the least? rank these systems in order from most to least in terms of favoring products rather than reactants. d > b > a > c c > a > b > d b > c > d > a a > d > c > b

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.