Archaeoastronomy: December 2010
This subatomic particle has a mass of. 0.000 000 000 000 000 000 000 000 001 672 kg. This is a tiny mass indeed. But in everyday quantities of matter there are a lot of atoms! For instance, in one kilogram of pure water, the mass of hydrogen atoms amounts to just slightly more than 111 grams, or 0.111 kg.
