You can use grams. To find out use a triple beam balance.
A small metallic paper clip has a mass of a little over one gram.
grams
I would go with centemeter to the nearest tenth (milieter).
The answer is either centimeters or millimeters.
Grams
Use centimeters or millimeters.
Paper clip APEX
a paper clip or a pencil
it is to clip paper so that the paper would not be flying around everywhere
grams; milligrams
If it is made of metal, it is a conductor.
inches or centimeters