law: Standards of Weights and Measures Act, 1976 
  11. Base unit of
  
  amount of substance. - 
  (1) The base
  
  unit of amount of substance shall be the mole.
  (2) The “mole” is the
  
  amount of substance of a system which contains as many elementary entities as
  
  there are atoms in 0.012 kilogram of carbon 12.
  (3) When the mole is
  
  used, the elementary entities shall invariably be specified and may be atoms, molecules,
  
  ions, electrons, other particle, or specified groups of such particles.