When an object loses its charge we say it has __________. This happens when electrons are able to __________. They will continue to __________ until the objects become equally charged. This means we now have __________ potential difference (__________) between objects.
The greater the charge on an isolated object the __________ the voltage (p.d.) between the __________ and __________. If the voltage becomes high enough, a __________ (spark) may jump from the object to an earthed __________.
Metals are good conductors because of their structure. Metallic structures have the __________ nuclei fixed in a lattice/matrix. Most of the electrons stay with their nucleus but the electrons in outer shells form a 'sea of electrons' able to move between the different nuclei.
Because they __________ each other, they are generally evenly distributed throughout the material. When there is an average movement of this 'sea' in one direction we have __________ flowing.
Different metals have different numbers of free electrons. The more free electrons in a material, the __________ a conductor it is. We would say that it has a high conductance or a low resistance. Objects that do not have 'free electrons' are unable to conduct electricity and are known as __________.
Current can be thought of the number electrons passing a point in a circuit, in a bit of time. This rate of flow of electrical charge is called the current.
Find out more in the Electical Power Topic