| Subject | 
is named after | 
has proposal date | 
has uncertainty | 
has definition | 
has equation | 
has value | 
has symbol | 
is a kind of | 
is an instance of | 
has temperature | 
has pressure | 
| physico chemical constant |   |   |   |   |   | changes in value are due solely to an increase in measurement accuracy or convention |   | fundamental physical constant |   |   |   | 
| Loschmidt constant | J. Loschmidt (1821-1895) | 1865 | 0.0000047 × 1025 m-3 | This is the number of molecules in a cubic metre of an ideal gas at s.t.p. It is equal to the Avogadro constant divided by the molar volume. In Germany it is sometimes called Avogadro's constant. |   | 2.6867775 × 1025 m-3 | n0 |   | physico chemical constant | 273.15 K | 101.325 kPa |