The average atomic mass of oxygen is the atomic mass with respect to 1/12th the mass of a C-12 atom, related to natural abundance.
amu - atomic mass units
O-16 - 15.995 amu
O-17 - 16.999 amu
O-18 - 17.999 amu
the average atomic mass is 15.9994 amu
average atomic mass = ∑atomic mass of each isotope * relative abundance percentage
in other words the average atomic mass is closer to the atomic mass of the most abundant isotope. In this case 15.9994 is closest to 15.995 amu which is the atomic mass of O-16.
This means that O-16 is the most abundant isotope.
The correct answer is C. There is no oxygen in space, so there can be no combustion.
Explanation:
Fire and flames are the result of a chemical process known as combustion. Moreover, for combustion to occur there are two essential elements. The first one is a fuel or a substance that releases energy and ignites, and the second one is an oxidant, which accepts electrons. This mix and reaction causes high temperatures and release of heat in the form of fire and flames.
This implies, that for fireballs or any other form of fire to exist there must be oxygen or any substance that replaces it. This does not occur in space because the levels of oxygen are extremely low, this means, at least oxygen is added fireballs are not possible in this context as there is no oxygen, and therefore no combustion (Option C).
