Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus?
A) that it once had a much stronger magnetic field than it does today
B) that the greenhouse effect on Venus must have been much weaker in the distant past
C) that it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space
D) that volcanoes on Venus did not outgas as much water as volcanoes on Earth
C
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A 4.0-cm tall object is placed along the principal axis of a thin, convex lens of 30.0-cm focal length. If the object distance is 40.0 cm, which of the following best describes the image distance and height, respectively?
a. 17.3 cm and 7.0 cm c. 120 cm and 1.3 cm b. 17.3 cm and 1.3 cm d. 120 cm and 12 cm
Neon signs require about 12,000 volts to operate. If the circuit uses a 120-volt power source, the ratio of primary to secondary turns on the transformer should be
A) 1 primary to 100 secondary. B) 100 primary to 1 secondary. C) neither of these
A charged particle moving perpendicular to a magnetic field has a magnet force on it. But when an observer moves with the particle, so that the particle has a relative velocity of zero with respect to the observer, one would expect there would be no magnetic force. Yet there is still a force. If it is not a magnetic force, then what is the source of this force?
a. It is an electrical force. b. It is due to the ether. c. It is a gravitational force. d. It is something other than any of the above.
What are the "rungs" of a DNA spiral made up of?
a. RNA b. four chemical bases arranged in pairs c. enzymes d. ribosomes e. proteins