Observing at a wide range of wavelengths, astronomers have detected more than ______ different molecules in the ISM
a. 10
b. 20
c. 50
d. 100
e. 150
e
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I the inductance and the capacitance both double in an LRC series circuit, the resonate frequency of that circuit will
A. decrease by a factor of 1?2. B. decrease by a factor of 1/4. C. increase by a factor of 2. D. increase by a factor of 4.
Which of the following works best for fusing hydrogen?
A) Hit the hydrogen nucleus with a neutron. B) Hit the hydrogen nucleus with an electron. C) Cool the hydrogen until the nuclei are at rest and then suddenly compress them. D) Bring the hydrogen nuclei together very slowly until they hold together. E) Heat it up to such a high temperature that collisions cause the nuclei to fuse.
The half-life of radioactive iodine-137 is 8.0 days. How many iodine nuclei are necessary to produce an activity of 1.0 ?Ci? (1 Ci = 3.70 × 1010 Bq)
A) 4.6 × 109 B) 7.6 × 1012 C) 2.9 × 109 D) 3.7 × 1010
A wave generated in a medium is a longitudinal wave when
a. there is a net transport of matter by the wave. b. the molecules of the medium are unable to exert forces on each other. c. molecular displacements are parallel to the wave velocity. d. molecular displacements are perpendicular to the wave velocity. e. the density of the medium is less than the density of water.