AbstractThe calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular ...

It is tempting to think that some materials are always heavier than other materials. For example, someone might say that metal is heavier than air. But it depends on how much of each material there is ...

Copper atoms are larger than aluminum atoms. There are fewer copper atoms than aluminum atoms in the cubes. Copper atoms are much more massive than aluminum atoms. The extra mass makes copper more ...