If you have a new question, ask an expert . My experiment is about the relationship between the length and resistance of constantan wire. The longer the wire, the greater its resistance. But the resistivity of the wire remains the same since it is a property of the material.
Metals have lots of freely moving electrons.
Other substances, such as glass, have few. Although all metals are pretty good conductors of electricity, they vary in how many free electrons are available and how easily they may move through the crystal structure of the metal. When an electrical potential is applied there is a tendency for the electrons to move towards the positive charge, so while the motion of the electrons is still random, the average of all the movements is in that direction. The energy of an electron may increase, but only by specific amounts, called quanta. An electron may be at one of several levels, but not in between.