By Riddhi Lodhia
Rea – Grace Maamari
Atoms and Isotopes
The nuclear model
Atoms contain three sub-atomic particles called protons, neutrons and
electrons. The protons and neutrons are found in the nucleus at the centre
of the atom, and the electrons are arranged in energy levels or shells around
All the atoms of a given element have the same number of protons and
electrons. However, the number of neutrons can vary. Atoms of the same
element that have different numbers of neutrons are called isotopes of that
element. The diagram shows three hydrogen isotopes.
How does Nuclear Power Work?
Uranium and plutonium
The main nuclear fuels are
uranium and plutonium. These
are radioactive metals. Nuclear
fuels are not burnt to release
energy. Instead, the fuels are
involved in nuclear reactions in
the nuclear reactor, which
leads to heat being released.
The rest of the process
process using fossil fuels. The
heat of generating electricity is
then identical to the energy is
used to boil water. The kinetic
energy in the expanding steam
spins turbines, which then
drive generators to produce
Advantages and Disadvantages
Unlike fossil fuels, nuclear
fuels do not produce carbon
dioxide or sulfur dioxide.
Like fossil fuels, nuclear fuels
are non-renewable energy
resources. If there is an
accident, large amounts of
radioactive material could be
released into the environment.
In addition, nuclear waste
remains radioactive and is
hazardous to health for
thousands of years. It must be
There are three main types of radiation, called alpha, beta and gamma
radiation, which all have different properties. Radiation can damage cells
and make them cancerous. Very high doses of radiation can kill cells. It can
be detected using photographic film or a Geiger-Muller tube. Radiation
badges are used to monitor the level of radiation that people who work with
radioactive sources are exposed to.
Alpha radiation consists of alpha particles. An alpha particle is identical to
the nucleus of a helium atom, which comprises two protons and two
Beta radiation consists of high energy electrons emitted from the nucleus.
These electrons have not come from the electron shells or energy levels
around the nucleus. Instead, they form when a neutron splits into a proton
and an electron. The electron then shoots out of the nucleus at high speed.
Gamma radiation is very short wavelength (high frequency) electromagnetic
radiation. This is similar to other types of electromagnetic radiation such as
visible light and X-rays, which can travel long distances.