When was the metric system invented?

A chronology of the metric system (http://lamar.colostate.edu/~hillger/dates.htm)

It depends on what you mean by "metric system" and "invented" :)

What metric system unit of measurement is used for weight?

Wow your dumb

wow your dumb

Before judging anyone,please make sure you do good first OK... "your" there is a large mistake... it should mean you are so it should be "you're"... learn from it...