6
ELECTRiCiTY: A mYSTERiOUS fORCE
Electric energy is used to light streets, to
move trains and to make domestic appliances
work, like washing machines and fridges.
Electricity is an energy that can be measured
but is hardly ever seen by the naked eye.
Although
electricity
is not a difficult topic,
it is important to learn several concepts to
understand it better.
This invisible force was first discovered
about 600 BC by the Greek philosopher
Thales. However, it was only 2000 years
later when scholar William Gilbert named
it
electricity, from the Greek word “electron”
that means amber. To understand the nature
of this mysterious force, you first need to
understand the small particles called
atoms
.
Atoms are made up of three different types of
even smaller
particles, which are called
protons, electrons
and
neutrons
.
Protons have a positive charge, electrons have a negative charge
while neutrons have a neutral charge (you can also say they have
no charge). Protons and neutrons are found in the nucleus of the
atom, which is right in the centre. While electrons whirl around
the atom and generate a negatively charged energy. The number
of protons an atom has is known as the
atomic number
.
The number of protons and electrons in an atom
has to be equal, so if for some reason
an electron is pushed away from the
atom, it will jump to another atom to
find another proton.
This creates a chain reaction, which
is commonly known as electricity.
ELECTRiC ENERGY TRANSfORmED
fROm CHEmiCAL ENERGY
Electric energy can come from different forms of energy such as
chemical energy. Batteries allow us to transform chemical energy
into electric energy.
A battery is made up of two bars, called
electrodes
, which are
immersed into a chemical solution made of an equal number of
particles with positive and negative charge. A bar has a
positive
pole
(marked with a “+”) and a
negative
pole (marked with a “-”).
When we connect the two poles of the battery, for example, to a
bulb, a chemical reaction takes place. This allows the electrons to pass
from the negative to the positive pole for a certain amount of time,
and causes the bulb to light up. This flow of electric particles is called
electric current. However, despite the fact the electrons actually move
from the negative to the positive pole, people generally say that the
electric current flows from the positive to the negative pole.
Let’s find out about some electric components!
pROTON
ELECTRON
NEUTRON
pOSiTivE pOLE
ELECTRODES
NEGATivE pOLE
NEGATivELY CHARGED pARTiCLE
pOSiTivELY CHARGED pARTiCLE
ELECTRO
LAB
