Magnesium has 12 protons. How many electrons are in its third energy level?
a. two
b. four
c. six
d. eight
e. ten
a
You might also like to view...
Which of the following is NOT one of the four stages in the development of a terrestrial planet?
a. flooding b. cratering c. slow surface evolution d. fusion of hydrogen to helium e. differentiation
Series/Parallel Circuits: A resistor is made out of a wire having a length L. When the ends of the wire are attached across the terminals of an ideal battery having a constant voltage V0 across its terminals, a current I flows through the wire. If the wire were cut in half, making two wires of length L/2, and both wires were attached across the terminals of the battery (the right ends of both wires attached to one terminal, and the left ends attached to the other terminal), how much current would the battery put out?
A. 4I B. 2I C. I D. I/2 E. I/4
It takes 10 J of work to push a charge into an electric field. Relative to its starting position it has gained a potential energy of
A) less than 10 J. B) 10 J. C) more than 10 J. D) none of the above
A piece of uranium can be made into nuclear explosive only after it is purified into uranium-235, because
A. the other naturally occurring isotopes of uranium interfere with efficient chain reactions. B. uranium-235 is the heaviest isotope known to mankind. C. it has to be soldered with lead for safety. D. before purification, the uranium-235 nucleus will not split apart.