Electricity flows through a conductor
Whenever a potential difference is applied between a conductor the electron flow through the conductor. This generates a conductor. If the flowing electrons collide with atoms in the conductor this causes resistance.
Resistance generates heat.
As the electrons collide with atoms, some of the kinetic energy is wasted, and transferred to the atoms. This increases the temperature of the conductor.
Higher resistance → Higher temperature
Different conductors offer different levels of resistivity to the current. A higher resistivity means electrons collide more, with the atoms, with impurities or with each other. More collisions mean a greater increase in temperature.
And as the temperature increases, so does the glow
Now, we're getting close to making a bulb. If we can get the conductor hot enough, it will begin to glow faint red and finally the characteristic yellow of a light bulb.
Finally Bulb glow
