Scientific Ontology

n

Base SI

Amount of Substance

Number of elementary entities; an SI base quantity.

mole (mol)

Dimension: $[\,N\,]$

How values of amount of substance span the physical world (in mol, log scale).

Single molecule

1.66 × 10^-24 mol

Glass of water

1.40 × 10¹ mol

Lower limit10^-24 molUpper limit10² mol

Ideal Gas Law

p V = n R T

Ideal Gas Law (Boltzmann form)

pV = Nk_BT

Radioactive Decay

N = N_0 e^{-\lambda t}

Activity

A = \lambda N