The student wants to emphasize the thickness of lead-208’s neutron skin. Which choice most effectively uses relevant information from the notes to accomplish this goal?
A
The neutron skin surrounding an atom of lead-208 measures about 0.28 trillionths of a millimeter.
B
Atoms with excess neutrons will often acquire a neutron skin.
C
An atom of lead-208, like some other atoms, is surrounded by a neutron skin.
D
Neutrons surround the surface of an atom of lead-208.
Explanation
Correct answer: A.
Choice A is the best answer. The sentence emphasizes the thickness of lead-208’s neutron skin, noting that it is about 0.28 trillionths of a millimeter thick.
Why the other choices are wrong
Choice B
Choice B is incorrect. The sentence makes a generalization about atoms, stating that atoms with excess neutrons will often acquire a neutron skin; it doesn’t emphasize the thickness of lead-208’s neutron skin.
Choice C
Choice C is incorrect. The sentence states that lead-208 has a neutron skin; it doesn’t emphasize the thickness of that skin.
Choice D
Choice D is incorrect. The sentence indicates that lead-208 is surrounded by neutrons; it doesn’t emphasize the thickness of lead-208’s neutron skin.