Hard water is due primarily to dissolved salts of which elements?
a. Zinc and copper
b. Calcium, iron, and magnesium
c. Sodium and potassium
d. Sodium and chlorine
b
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Compared to natural background radiation, the amount of radiation received by U.S. citizens from normally operating nuclear power plants is
A) about 10% as much. B) very much less. C) roughly the same amount. D) absolutely zero. E) considerably more.
Two sources of light illuminate a double slit simultaneously. One has wavelength 570 nm and the second has an unknown wavelength. The m = 5 bright fringe of the unknown wavelength overlaps the m = 4 bright fringe of the light of 570 nm wavelength
What is the unknown wavelength? A) 456 nm B) 326 nm C) 380 nm D) 713 nm
For relaxed viewing with a microscope or a telescope, the eyepiece is adjusted to place the image at
A) the near point of the eye. B) the pupil of the eye. C) the focal point of the eyepiece. D) infinity. E) the focal point of the objective lens.
Refraction occurs for both sound and light. When refraction occurs there is a change in
1) frequency. 2) wavelength. 3) speed. 4) all of the above. When sound travels faster near the ground than above, bending of sound tends to be 5) upward. 6) downward. 7) neither of these.