1. which of the following is not part of john dalton's atomic theory?
a. all elements are composed of atoms.
b. all atoms of the same element have the same mass.
c. atoms contain subatomic particles.
d. a compound contains atoms of more more than one element.
2. who provided evidence for the existence of a nucleus in an atom?
a. john dalton
b. j. j thomson
c. democritus
d. ernest rutherford

What is the h+ concentration for an aqueous solution with poh = 4.01 at 25 ∘c? express your answer to two significant figures and include the appropriate units.

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.

21. consider the following chemical reaction: n2+ o2 2 no if 10.0 g of n2 reacts with excess oxygen then how many grams of no can be formed? a) 10.7 g b) 21.4 g c) 32.9 g d) 42.8 g page 4 of 8