Why does iron, when added to quartz, cause the purple color of amethyst?
A) The presence of trace constituents can affect color.
B) Iron overpowers the silicon in quartz.
C) Amethyst is formed under extremely hot conditions.
D) Iron is red and silicon is blue, making purple.
Answer: A
You might also like to view...
Science and technology are
A) related to one another, but are not the same thing. B) responsible for all the good in the world. C) responsible for all the bad in the world. D) fundamentally different from each other.
Which statement about geostrophic gyres is true?
A) One of the six gyres is the Antarctic Circumpolar Current. B) Gyres are influenced by the Coriolis effect and the position of continental landmasses. C) Gyres are formed by deep water currents that flow in a continuous circuit around the five major basins. D) Sea level is lower in the middle of the gyre.
The basic strategy of the OPEC cartel is to
A) assure that developed nations get as much crude as oil as they need. B) give priority to developing nations who want to use oil to boost industrial progress. C) produce all their proven reserves as quickly as possible to keep prices and demand high. D) control production and keep the market price as high as possible without discouraging major buyers.
Which subtropical boundary current is faster, narrower and deeper than its counterparts?
A) Eastern Boundary Current B) Equatorial Current C) Northern Boundary Current D) Southern Boundary Current E) Western Boundary Current