Half-life period polonium

Radium is chemically similar to barium it displays a characteristic optical spectrum its salts exhibit phosphorescence in the dark, a continual evolution of heat taking place sufficient in amount to raise the temperature of 100 times its own weight of water 1°C every hour and many remarkable physical and physiological changes have been produced. Radium shows radioactivity a million times greater than an equal weight of uranium and. unlike polonium, suffers no measurable loss of radioactivity over a short period of time (its half life is 1620 years). From solutions of radium salts, there is separable a radioactive gas radium emanation, radon, which is a chemically ineit gas similai to xenon and disintegrates with a half life of 3.82 days, with the simultaneous formation of another radioactive element, Radium A (polonium-218). 

As decay occurs, the remaining activity declines. The time it takes for a radionuclide to lose half its activity is its half-life (ti/2), which may range from extremely short to extremely long periods. The half-lives of polonium-214 and uranium-238, for example, are 163.7ps and 4.46x10 years, respectively. As individual isotopes decay they can form new stable or unstable isotopes in a series of steps that eventually ends in a stable nucleus. The type of decay and the half-lives of the intermediaries in a decay series is characteristic of the isotope e.g., radioactive thorium-232 undergoes the following decay steps to result in a stable isotope of lead ... 

Polonium-210 has a half-life of 138.4 days, decaying by alpha emission. Suppose the helium gas originating from the alpha particles in this decay were collected. What volume of helium at 25°C and 735 mmHg could be obtained from 1.0000 g of polonium dioxide, P0O2, in a period of 48.0 h ... 

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