3.1 Static Electricity Flashcards
What does neutral matter contain?
An equal number of positive and negative charges
What is static electricity?
The build up of charge on insulating materials and can cause sparks when it’s discharged
Describe how static electricity can occur
- When certain insulating materials are rubbed together, negatively charged electrons will be scraped off one and dumped on the other.
- This will leave the materials electrically charged, with a positive static charge on one and an equal negative static charge on the other.
- Which way the electrons are transferred depends on the two materials involved.
- If enough charge builds up, it can suddenly move, causing sparks or shocks.
Describe why static electricity does not occur on conducting materials?
In conducting materials like metal where the electrons are able to move, the electrons just flow straight back again and so no charge ever builds up
Describe how electrons move between a polythene rod and a cloth
The electrons move through the duster to the rod. This leaves a positive static charge on the cloth and a negative static charge on the polythene rod.
Describe how electrons move between an acetate rod and a cloth
Electrons move from the rod to the duster. This leaves the rod with a positive static charge and the cloth with a negative static charge.
Describe how sparks form from static electricity once there is a negatively charged material
As the charge of the material increases, a potential difference will develop between the charged material and the Earth or any earthed object. If the potential difference is large enough, the electrons can jump across the gap and that jumping of electrons is called a spark.
When two materials are rubbed together, which particles are transferred?
Electrons
What charge will a material that gains additional electrons have?
Negative charge
