What fundamental unit of the metric system always has a prefix in front of it?

Kilogram

Explanation:

The metric system is the Kilogram, meter, second system. These are fundamental quantities of the metric system.

Kilogram, the unit of mass always carries the prefix 'kilo' in its SI unit. Kilogram is the SI unit of mass. Hence, the fundamental unit on the metric system that always has a prefix in front of it is kilogram.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.