REPORTING TITLE OR TOPIC: RADIOACTIVITYY

REPORT
RADIOACTIVITY

1. RADIO
ACTIVITY
PALMA, REVEN JADE
BILAN, CRISSELDA
LUCAS, DIANNE CHRISTIE
RADIO
ACTIVITY

2. BORN: DECEMBER 15, 1852
PARIS, FRANCE
1
ANTOINE HENRIBECQUEREL
DIED: AUGUST 25, 1908
(age 55 years)
Le, Croisic, France
Known for: Discovery
of Radioactivity
Awards: Rumford Medal (1900)
Nobel Prize in Physics in 1903 w/
Pierre and Marie Curie for the
discovery of Radioactivity

3. Becquerel entered the Polytechnic in 1872, then
the government department of Ponts - et -
Chaussées in 1874, becoming an engineer in 1977
and being promoted to chief engineer in 1894
2
EDUCATIONAL BACKGROUND
In 1888 he acquired his doctorate with his
dissertation on the absorption of light by crystal.
From 1878 he had held an appointment as an
Assistant at the Museum of Natural History, taking
over from his father in the Chair of Applied Physics
of the Conservatoire Des Arts et Metiers
Then in 1892 he was appointed Professor of
Applied Physics in the Department of Natural
History at the Paris Museum
He then later became a Professor at the
Polytechnic in 1895

4. In late February 1896, Henri Becquerel was experimenting with
phosphorescent uranium salt crystals which glow for a time
after exposure to sunlight. He placed the crystals on
photographic paper, and saw that a black shadow was visible
where the crystals were when the paper was developed. He
initially thought the crystals were emitting X-rays when exposed
to sunlight. However, on leaving the crystals on the paper in a
dark cupboard during overcast days, he found shadows were
still visible on the developed paper, and that the process was
independent of sunlight. Marie Curie coined the term "radiation"
in 1898.
INTRODUCTION
3

5. INTRODUCTION
4

6. DISCOVERRY
5
Becquerel's discovery was
confirmed by the Polish
physicist Marie Curic, who
showed that the activity of
uranium sats depended
only em the amount of
uranfim they contained
and not at all on the
physical store or chemical
composition of the salt.
01
We now understand why
this is -radioactive
emissions come from the
nuclei of particular atoms
so they are not affected
by bonding (which
concerns the outer
electrons) or physical
conditions (like
temperature, pressure,
etc.).
02

7. Marie Curie made several other
important discoveries in this field.
She showed that thorium is also
radioactive and noticed that some
ores of uranium, pitchblende and
chalcolite, are more active than
uranium itself. She thought this must
be due to new radioactive elements
inside them and sison discovered
radium and polonium, which are
highly radioactive.
6
01
Because Curie was unaware that
these radiations were dangerous,
she took no safety precautions as
she worked with them, and her
notebooks are still too radioactive
to handle even today! She shared
the 1903 Nobel Prize for Physics
with her husband Pierre, and with
Bocquerel
02
MARIE CURIE

8. 7
There are three types of
radioactive emission, called
alpha, beta, and gamma
radiation.
These can be separated by
electric or magnetic fields.
01
Radioactive emissions cause
ionization, alpha radiation
being most strongly ionizing
and gamma radiation least
strongly ionizing.
Ionization is the property used
to detect and measure
radioactivity
02
EARLY DISCOVERIES

9. The more strongly ionizing the radioactivity is, the more rapidly it dissipates
its energy when it passes through materials. The ranges for similar energy
emissions are in the order
gamma > beta > alpha
8
03
The activity of a source is independent of physical conditions and chemical
bonding, depending only on the type of atom involved and the number of
these atoms present
04
EARLY DISCOVERIES

10. Problem
9
Each atom has a nucleus
and radioactive decays
involve nuclear
transformation
Alpha particles are helium nuclei emitted
from the nuclei of some radioactive
atoms. This was shown by stopping the
alpha particles inside a sealed container
where they captured two electrons and
became helium atoms.
Beta particles are electrons emitted from the
nuclei of some radioactive atoms (they are
created in the decay and are not related to
the orbital electrons in any way). This was
shown by measuring thei deflection in a
magnetic field and showing they had the
same charge-to-mass ratio fem) as an
electron
Gamma rays are high-energy
electromagnetic photons emitted from
the muclei of some radioactive atoms
following an alpha or beta decay These
are not deflected in electric or magnetic
fields. Their properties are identical to
those of hard X-rays
EARLY DISCOVERIES

11. BORN: August 30, 1871
SPRING GROVE, NEW
ZEALAND
10
RUTHERFORD
ERNEST
DIED: October 19, 1973
CAMBRIDGE, ENGLAND
(aged 66)
AWARDS AND HONORS:
COPLEY MEDAL (1922)
NOBEL PRIZE (1908)
SUBJECTS OF STUDY:
RUTHERFORD MODEL
ATOM AND RADIOACTIVITY

12. BORN: September 2, 1877
EASTBOURNE, SUSSEX
11
SODDY
FREDERICK
DIED: September 22, 1956
BRIGHTON, SUSSEX
(aged 79)
AWARDS AND HONORS:
NOBEL PRIZE (1921)
SUBJECTS OF STUDY:
CHEMICAL ELEMENT
DISPLACEMENT LAW ISOTOPE
AND RADIOACTIVITY

13. 12
RUTHERFORD AND SODDY WORKED OUT THE RULES FOR
RADIOACTIVE.
ALL DECAYS CONSERVE TWO FUNDAMENTAL PROPERTIES:
CHARGE
NUMBER OF NUCLEONS
NUCLEAR
TRANSFORMATION

14. Apha decay is the emission of a helium nucleus from
the nucleus of a heavy radioactive element.
13
ALPHA DECAY
Beta decay is the emission of a fast electron from the
nucleus of a radioactive element.
BETA DECAY
NUCLEAR
TRANSFORMATION

15. Hanover University
Gamma rays are emitted when excited nuclei make quantum
jumps to lower energy levels (similar to the photons emitted
by quantum jumps of electrons in atoms, but much higher
energy).
Gamma-ray emission does not affect the type or number of
particles present in the nucleus.
Sometimes excited states are represented using an asterisk.
14
GAMMA RAYS
NUCLEAR
TRANSFORMATION

16. THANK
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