Are electrical properties measured using the International system of units (SI)?
The term "metric system" is not the correct terminology. We use the SI, the International System of Units that defines certain base units as well as a much larger set of derived units. The base units must be defined in terms of reproducible physical phenomena, then the derived units are defined in terms of the base units.

The ampere is a base unit. According to IEEE/ASTM standard SI 10-2016:


  The ampere is that constant current that, if maintained in two
  straight parallel conductors of infinite length, of negligible
  circular cross section, and placed one meter apart in a vacuum, would
  produce between these conductors a force equal to \$2\times 10^{-7}\$
  newton per meter of length.


The volt, the farad, the coulomb, etc. are derived units.

The SI does not say that you can or can not use exponential notation and it does not specify what "engineering notation" would be. It tells you what letter to use for the symbol for a unit (e.g. F for farad) and specifies the prefixes that can be used instead of exponential notation. There are quite a few other rules and suggestions...too many to include here.