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Thorium
Radium
Ordinary water
Which among the following is a positively charged particle emitted by a radioactive element
Atoms are composed of
In an atomic explosion, enormous energy is released which is due to
Isotopes are separated by
The wavelength of X-rays is of the order of
Mesons are found in
Which radioactive pollutant has recently drawn to public, due to its occurrence in the building material
Shows the masses of the three elementary particles in decreasing order
What is the wavelength of visible spectrum
Which of the following has a least penetrating power
