Radioactive half-life — UPSC Physics Optional CSE 2005 Paper II

(i) Write the Weizacker mass formula and explain the significance of various terms. (ii) Determine the amount of {}_{84}^{210}\text{Po} necessary to provide a source of \alpha-particles of strength 5 \text{ mC}_i. The half-life of {}_{84}^{210}\text{Po} is 138 \text{ d}.