The large connected urban area from boston to washington, dc, is often referred to as a(n) a. metropolis b. megalopolis c. suburb d. urban zone

The correct answer is option B, Megalopolis

When two or more large metropolitan cities are so nearing in their geographical boundaries that they merge to form a large urban area known as Megalopolis. The merging cities have high end integrated infrastructure and possess a high density population. As per Gottmann, Megalopolis can  be referred to as a large functional urban region. The region between Boston and Washington DC include several other cities like New York, Providence, Hartford, New Haven, Philadelphia and Baltimore is the most prominent Megalopolis region of Washington DC.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.