Electric charge
Définition :
Electric charge it is a scalar quantity, representing a fundamental property of matter that helps explain certain phenomena (electrostatics, electromagnetism, etc.).
There are two types of electric charge, positive and negative.
Elementary charge: This is the smallest amount of charge Q= |e| = 1.602176634x10-19 C
the electrical charge of an:
electron : Qe = -e = -1.602176634x10-19 C
and proton : Qp = +e = +1.602176634x10-19 C
Two charges of the same sign repel each other, and two charges of opposite signs attract each other.
Définition : Point charge
it is an electric charge localized at a dimensionless point.
Définition : conservation of electric charge
In an isolated body, the algebraic sum of electric charges remains constant: qfinal = qinitial