9.1 Electrostatics and electric currents Flashcards
Charges
Where are the charges in an atom?
The protons in the nucleus of an atom have a positive charge. The electrons moving in the shells of an atom have a negative charge. Since atoms have the same amount of electrons and protons, the charges cancel each other out, and the atom has no overall charge.
What makes electrons move from one object to another so that the object gains an electrostatic charge?
Friction between objects.
What makes an object positively charged?
Losing electrons by transferring them to another object and leaving a larger number of protons in each atom, giving it an overall positive charge.
What happens when an object gains electrons?
The object gains an negative charge because there are now more electrons in the atom than protons, so the atoms now have an overall negative charge.
What is an atom with a charge called?
An ion.
What is the law of electric charges?
Like charges repel and opposite ones attract.
Why are electrons held together in atoms?
Because they are attracted to the positively charged protons in the nucleus of an atom.
When does static electricity occur?
When there is a build-up of electric charge on the surface of a material.
What are the three ways objects can be charged?
Friction, Conduction and Induction
How does friction charge an object?
When two objects are rubbed together, the electrons move and both objects gain a charge.
How does conduction charge an object?
When electrons move from one object to another through direct contact.
How does induction charge an object?
When charges in an uncharged object are rearranged without direct contact with a charged object.
