The rock pumice often floats yet the density of the rock is greater than water. Why does it float?
A) Pumice is a pyroclastic rock derived from rhyolite glass, and rhyolite glass has a lower density than water.
B) Pumice is a pyroclastic rock comprised largely of open voids formed by gases released when the magma solidified as froth-like material.
C) Pumice is another name for dacite, a low-density rock that floats in water.
D) Pumice is a rock made of rhyolite glass that erupts into water, which traps water in voids and makes the material less dense than water.
B
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Which of the following is true about the water table?
A) The shape of the water table does not mimic topography. B) Deeper water below the water table must flow in the same direction as near-surface water. C) The water table can slope in opposite directions beneath a hill. D) All of these are correct. E) None of these are correct.
A mirage will appear to be looming when:
A) there is a strong negative lapse rate. B) air is very unstable. C) it appear smaller than the actual object. D) there is a strong temperature inversion.
Most fresh water fish are hypertonic, meaning their body cells contain more salt than the surrounding water. Since osmosis should push water into their cells, why don't they explode?
a) They urinate a lot, so the water does not build up. b) They don't drink any water because they get so much from osmosis. c) Their cells have adapted to absorb salt. d) They have adapted to live with high osmotic pressure. e) All of the above
Judge the following sentence according to the criteria given below: Seismologists prefer the well-known Richter scale over the moment magnitude scale BECAUSE the Richter scale is better for larger-magnitude earthquakes
A) The assertion and the reason are both correct, and the reason is valid. B) The assertion and the reason are both correct, but the reason is invalid. C) The assertion is correct, but the reason is incorrect. D) The assertion is incorrect, but the reason is correct. E) Both the assertion and the reason are incorrect.