Chapter 42 - Static and Current Electricity Flashcards
When there are more protons in an atom then electrons, we say the object is ___________ charged
Positively
When there are more electrons in an atom than protons, we say the object is ___________ charged
Negatively
When we remove electrons from an object, the object becomes…
Positively charged
When we add electrons from an object, the object becomes…
Negatively charged
What is the usual way to remove electrons from an object?
Friction
What is the usual way to give electrons back to an object?
Friction
Like charged objects _____ each other
Like charged objects repel each other
Oppositely charged objects ______ each other
Oppositely charged objects attract each other
Insulator
A material through which charge cannot flow
Conductor
A material through which charge can flow
How is lightning formed?
○Tiny water droplets in a cloud can sometimes become charged by friction in the air
○If the droplets gain electrons, a negative charge can build up in the cloud. This charge is attracted to earth
○It travels to earth through the air
○The air becomes very hot. So hot that it emits light and this is called lightning
How does a lightning rod work?
○Made of a good conducting metal such as copper
○Sharp, metal rod placed above the tallest part of the building
○If lighting hits the rod, electrons travel to earth along the copper conducor and the building is undamaged
Current electricity
Flow of electrons along a wire
What is the unit for current?
Amp (A) (ampere)
Voltage
The measure of the ability of electrons to do a particular task
