Wavelength is a length. The SI unit for length is the meter (m).
The unit of measure used to describe electrical "pressure" is the "Volt."
The smallest unit of measurement used to describe the storage capacity of a computer is a "bit".
The metric unit most often used to describe weight is the Kilogram.
wavlength is the length of a wave
a ruler
A litre.
No units - its a ratio.
Curie or Becquerel
A scale
the shortest of all rays
Kilogram.
g/m³ or mg/l