Sodium. It reacts with most of every other element.
The answer to the question is D.
The answer is (3)Ne. Usually, the elements belongs to group 18 all have completely filled valence electron shell. Among the four elements carbon, vanadium, neon and antimony, only neon belongs to group 18.
Robert Boyle, the 17th century British chemist, first noticed that the volume of a given amount of gas is inversely proportional to its pressure when kept at a constant temperature. When working with ideal gases we use PV = nRT, but remember n, R, and T are all constant. Therefore we have:
PV(before) = PV(after)
P(0.5650) = (715.1)(1.204)
Protons in science is positive