On Tuesday 14 February 2006 14:29, Bill Hooper wrote: > There are a few exceptions that are allowed for use with SI (but not > part of the coherent set of SI units). These include the litre, the > hectare and the tonne. (Even with the litre, the use of SI prefixes > is discouraged. Instead of millilitres, the equivalent cubic > centimetres is preferred. Instead of kilolitres, the equivalent cubic > metres should be used. And instead of megatonnes, the equivalent > terragrams should be used.)
I would use prefixes with the liter and the are, but not with the tonne. Except for the yottatonne and the zettatonne, all power of 1000 prefixes applied to the tonne result in some prefix on the gram, but the nanoliter, picoliter, attoliter, zeptoliter, petaliter, exaliter, and yottaliter cannot be expressed as cubic <prefix>meter, nor the kiloare, megare, or any others except the are itself and the microare as square <prefix>meter. phma
