2. table
of
contents:
01 INTRODUCTION
03
BACKGROUND & HISTORY
02
What is Radioactivity?
What is the Importance of
Understanding Radioactivity?
First Evidence of Radiation
Contributors in the Field of Radioactivity
NATURE OF RADIOACTIVITY
Unstable Nuclei: Will it Release Energy?
Natural & Artificial Radionuclides
a. Early Observations of
Natural Sources of Radiation
b. Initial Experiments Leading to
the Discovery of Radioactivity
What Causes Radioactivity?
a. Examples & Applications in Real Life
4. Originates from the Latin word “radius”, meaning “ray”
and “activus” meaning “activity”. So, it is Radiation
Activity.
what is
radioactivity?
Radioactivity refers to the spontaneous emission of
radiation, typically in the form of particles or
electromagnetic waves, from the nucleus of an unstable
atom. This emission occurs as a result of nuclear decay
processes within the atom, which may involve the
release of alpha particles (helium nuclei), beta particles
(electrons or positrons), gamma rays (high-energy
photons), or other types of radiation. The phenomenon
of radioactivity is governed by the instability of certain
atomic nuclei, which undergo radioactive decay to
achieve a more stable configuration.
Antoine Henri Becquerel
Pierre and Marie Curie
6. EARLY OBSERVATIONS OF
NATURAL SOURCES OF
RADIATION
In the late 19th century, several
pivotal discoveries laid the
groundwork for our
understanding of natural
sources of radiation.
FIRST EVIDENCE OF
RADIATION
7. X-rays by Wilhelm Conrad
Roentgen (1895)
In November 1895, Wilhelm Conrad
Roentgen stumbled upon X-rays while
experimenting with cathode rays.
Roentgen’s discovery revolutionized
medicine and led to the widespread
use of X-rays for diagnostic purposes
8. Radioactivity by Henri Becquerel
(1896)
In March 1896, Henri Becquerel
discovered natural radioactivity. He
found that certain uranium
compounds emitted radiation
spontaneously.
This marked the beginning of our
understanding of radioactive decay
and the release of energy from
unstable atomic nuclei
9. Marie and Pierre Curie’s Work
(1898)
In December 1898, Marie and Pierre
Curie produced two radioactive
elements: polonium and radium.
Marie Curie’s tireless efforts in
isolating radium and studying its
properties earned her two Nobel Prizes
—one in Physics (1903) and another in
Chemistry (1911)
10. In 1896, Henri Becquerel stumbled upon the phenomenon of
radioactivity quite serendipitously. While researching the
fluorescence of uranium salts, he devised an experiment involving
naturally fluorescent minerals.
INITIAL EXPERIMENT LEADING TO THE DISCOVERY OF
RADIOACTIVITY
11. Here’s how it unfolded:
Becquerel wrapped photographic
plates in black paper to prevent
sunlight from reaching them.
He then placed crystals of uranium
salt on top of the wrapped plates
and set up the entire arrangement
outside in the sun.
His initial hypothesis was that the
uranium absorbed sunlight energy
and emitted it as x-rays.
However, on the 26th and 27th of
February, Paris experienced overcast
weather, causing his experiment to “fail.”
Despite the unfavorable conditions,
Becquerel decided to develop the
photographic plates anyway.
To his astonishment, the images on the
plates were strong and clear, proving
that the uranium emitted radiation
without an external energy source like
the sun.
This accidental discovery marked the
birth of radioactivity.
12. Heading
Subheading
Body
The term “radioactivity” was later coined by
Marie Curie, who, along with her husband Pierre,
delved into investigating the phenomenon
discovered by Becquerel.
The Curies extracted uranium from ore and found
that the leftover ore exhibited more activity than
pure uranium. This revelation eventually led to
the discovery of other radioactive elements,
including polonium and radium.
27. What happens if a
nucleus is unstable?
Will it release
energy?
An unstable nucleus will release energy
during radioactive decay in the form of
radiation, such as alpha particles, beta
particles, or gamma rays, until it reaches a
more stable state.
29. Radioactivity is caused by the
instability of atomic nuclei.
Atoms consist of protons,
neutrons, and electrons. In
some elements, the
arrangement of protons and
neutrons in the nucleus is not
stable. When the nucleus is
unstable, it may undergo
spontaneous changes, called
radioactive decay, to achieve
a more stable configuration.
30. Health and Safety:
Understanding radioactivity is crucial for assessing
and mitigating health risks associated with exposure
to radioactive materials.
Medical Applications:
Radioactive isotopes are widely used in medicine for
diagnostic imaging, cancer therapy, and various
medical treatments.
Energy Production:
Nuclear power generation relies on controlled
nuclear reactions to produce electricity, necessitating
a deep understanding of radioactivity for safe
operation.
what is the importance of
understanding radioactivity?
31. Environmental Impact:
Radioactive contamination from nuclear accidents or
improper waste disposal can have significant
environmental consequences, requiring an
understanding of radioactive substance behavior.
Scientific Advancements:
Radioactivity is fundamental to nuclear physics,
chemistry, and research, leading to insights into atomic
structure, nuclear forces, and decay processes.
National Security:
Understanding radioactivity is essential for arms
control, disarmament, and non-proliferation efforts, as
radioactive materials are used in nuclear weapons.
what is the importance of
understanding radioactivity?
33. NATURAL RADIONUCLIDES
ARTIFICIAL RADIONUCLIDES
are atoms found in nature that emit
radiation spontaneously. They are
not created by humans but exist
naturally in the environment.
are radioactive isotopes that are
not naturally occurring and are
typically created through nuclear
reactions in laboratories or
nuclear reactors.
35. Cosmic radiation mainly produces carbon 14 which
ends into vegetation.
Cosmic rays and radiation from rocks are sources of
external exposure for humans, while
radioelements inhaled in the air or ingested
through water and food generate internal exposure.
COSMIC
RADIATION
EARTH’S CRUST
RADIOELEMENTS
&
36. is a heavy metal with a variety of uses.Uranium can be
used for nuclear power generation and is also used in the
creation of nuclear weapons, among other purposes.
Because the radioisotope U-235 releases so much energy,
it can be used for efficient power generation in nuclear
power stations or in devastatingly powerful nuclear
weapons. it is often used as ballast in airplanes and boats
PRIMORDIAL
RADIOACTIVE
ELEMENT
URANIUM
38. Uranium emits gamma rays.
The sixth descendant of
uranium called – radon, – is
a gas.
Amounts of it can therefore
escape from the ground,
thereby releasing radiation
into the atmosphere.
39. Radon is a radioactive gas that has no
smell, colour or taste. Radon is produced
from the natural radioactive decay of
uranium, which is found in all rocks and
soils. Radon can also be found in water.
Radon escapes from the ground into the
air, where it decays and produces
further radioactive particles.
WHAT IS RADON?
40. OUR BODY ARE ALSO SLIGHTLY RADIOACTIVE
HOW?
The primordial radioisotopes which
exist (alongside their descendants)
within rocks on Earth can also be
found in trace quantities in
drinking water, vegetation and
food. These can then result in
internal irradiation, in conjunction
with the radioactive dust inhaled
with the air.
