What chemical formula would accurately describe an adult human being, in terms of the relative distribution of elements (including pollutants)? And what might be the formula for the first alien life form we encounter?
• One's "chemical formula" depends on a number of factors, most notably whether we're talking about a he or a she. Male bodies contain more water than female bodies, which have extra lipids. By weight, oxygen amounts to about two-thirds of the body, followed by carbon at 20 per cent, hydrogen at 10 per cent and nitrogen at 3 per cent. Elements originating from pollutants would only be present in trace amounts.
If a human body were broken into single atoms, we would arrive at an empirical formula H15750 N310 O6500 C2250 Ca63 P48 K15 S15 Na10 Cl6 Mg3 Fe1. The relative numbers of atoms in this differ from the composition by weight because atoms have ...
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