In static electricity, how do the elctrons move from one object to another?
I'm taking my GCSE physics (p2) this summer. I understand that only electrons move and not the positive charges. Do I need to know how or is it just friction?
(as I'm only GCSE, please don't go into too much detailed or I'll get so confused!!)
Electrons carry a negative charge. Since they are all charged alike, they tend to repel each other. When you have static electricity, which consists of a buildup of electrons on a surface, the electrons' mutual repulsion causes them to spread apart. The larger the available surface, the more they will spread.
When a charged surface is brought into contact with a second, noncharged surface, some of the electrons from surface #1 will spread onto surface #2 directly, until the charge density is even across both surfaces.
When the same surfaces are brought close together but not into contact, the electrons must jump across the gap. This can only happen if the charge difference between the surfaces is large enough. If it is, the air between the surfaces will become electrically charged, and will create a temporary conductive bridge that the electrons can travel across.