SPQR’s chemical formula depends on a number of factors. By weight, oxygen amounts to about two-thirds of the body, followed by carbon at 20%, hydrogen at 10% and nitrogen at 3%. Elements originating from pollutants would only be present in trace amounts (higher particle count to be found on or near weekends!) If SPQR was broken into single atoms, we would arrive at an empirical formula – Fe1 S15P48H15750Ai10O6500N3C2250 KI5T6Ng3103

The chemical elements in SPQR are distributed in various molecular and atomic species. An accurate formula could be expressed in the standard form: 7×1025H2O+9×1024pA6i6N12T+2×1024CH3(CH2)14+ ... and so on.

Metabolism, defined as the chemical and energy exchanges in a living body, means that any such chemical formula is continually changing.