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Scientific researches and discoveries

Marie Curie and Pierre Curie started working
together in laboratory. They performed their
early researches in difficult conditions as the
laboratory arrangements were not proper.
They had to undertake much teaching to earn
their bread and butter. Marie chose to work on
Wilhelm Roentgen’s discovery of X- rays and
discovery of radiation in Uranium by Henri
Becquerel.

She adopted this study of Henri Becquerel as
her thesis topic. At first, she was curious about
source of high energy emissions. She found
that Uranium showed no visible chemical
transformation, no change in appearance and
no appreciable change in state.

So, the source of energy emission remained fundamental scientific understanding that
undetectable. She was amazed whether the atoms are not essentially stable. She measured
emitted rays were defying the first law of the intensity of Uranium rays by electrometer
thermodynamics, the law of conservation of invented by Pierre and his brother.
energy. She made a important hypothesis that
emission of rays by Uranium containing She deduced that amount of radiation
mineral could be an atomic property of the depend on the amount of element present in
element Uranium. the mineral.She began to study if there are
other elements that also emitted the same type
It was a bold and revolutionary statement of radiation. She discovered that Thorium also
atom as atom was thought to be the most emitted radiation. She concluded that some
fundamental particle , the one which is indivisible. unknown substance, very active was present
Curie’s hypothesis would revise the in those minerals.

Radio activity

Pierre and Curie discovered the existence of Polonium and Radium in
1898. Then, they isolated radioactive radium salts from the mineral
pitchblende in their laboratory in Paris. Curie described the
elements an ‘radioactive’. She coined the term ‘radioactivity’
based on the Latin word for ray to describe the behaviour of Ura-
nium and Thorium and defined as the activity of rays that are
dependent on Uranium’s atomic structure, the number of atoms
of Uranium. Marie Curie defended her thesis on the new
radioactive substances in 1903 and gained her Doctor of Science
degree in the same year. In 1903, Pierre Curie and Marie Curie
along with Becquerel were awarded the Nobel prize for Physics.
Their second daughter Eve was born in 1904. Pierre’s life was short
, he died in a road accident in 1906.

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