A. What is the mass of a pencil or pen?
The mass will depend on the amount of material that comprises the pencil or the pen. Mass is an intrinsic property that you can calculate by taking a measurement of the weight using the formula: w = mg. Where (g) is the acceleration on the mass due to gravity (provided it is "close" to the Earth's surface).
A couple of examples:
If a pen weighs 1 lb (a seriously heavy pen), then its mass would be
m = 1 lb/32 (ft/s2) = 0.03125 slugs (slug is the unit of mass in the British system)
Likewise if a pen weighs 1 N, then its mass would be
m = 1N/9.81 (m/s2) = 0.1019 kilograms