Galactic disks appear blue because
A) they contain no G, K, or M dwarfs.
B) they contain only blue reflection nebulae.
C) dust obscures the longer, red, wavelengths.
D) O and B blue giants are much brighter than G, K, or M dwarfs.
E) dark matter gravitationally shifts all wavelengths towards the blue.
D
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Which of the following statements about nuclear fusion is not true?
A. It involves two or more small atomic nuclei slamming into each other and sticking together to make a larger atomic nucleus. B. It refers solely to the process of converting hydrogen into helium. C. It is the process that has made most of the elements of which we and the Earth are made. D. It is the process that generates the energy by which our Sun shines.
The mean free path of a gas molecule is:
A. the shortest dimension of the containing vessel B. the cube root of the volume of the containing vessel C. approximately the diameter of a molecule D. average distance between adjacent molecules E. average distance a molecule travels between intermolecular collisions
As minerals crystallize in cooling magma, are the minerals with lower amounts of silica or the minerals with higher amounts of silica the first to crystallize?
What will be an ideal response?
Heat will flow spontaneously from a cold object to a hot object
Indicate whether the statement is true or false