The electric charges
two kinds of electric charges:
- Positive electrical charges (+)
- Negative electrical charges (-)
electrical charges are comparable to north and south poles of magnets:
identical poles repel while different poles attract.
We can see a similar phenomenon with electric charges:
charges of same sign repel (two negative charges repel each other or
two positive charges repel each other).
- Electrical charges of opposite signs attract (positive charge and
negative charge attract).
The electric charge of electrons
are electrically charged particles:
Each electron carries a negative elementary charge denoted - e.
The term " elementary " means that there is no electric charge smaller.
3) Electric current in metals
a metal is a part of an electrical circuit including a generator, the
free electrons are influenced by positive and negative terminals of the
Because of their negative charge, electrons are repelled by the
negative terminal of the generator and are attracted by its positive
electrons are set in motion and this movement constitutes the electric
The free electrons move from the negative to the positive terminal:
that is the opposite of conventional direction of electric current