* Weight vs. Mass: Weight is the force of gravity acting on an object, while mass is the amount of matter in an object.
* Units: Grams (g) are a unit of mass, not weight.
* Length: The length of the pencil (20 cm) is irrelevant to its mass.
Therefore, the mass of the pencil is 3 grams.
It's important to use the correct terminology and understand the difference between weight and mass.
