Question

The mass of U${}^{234}$ of radioactivity $1$ curie is

• A. 3.7 x 10${}^{10}g$
• B. 3.7 x 10${}^{-10}g$
• C. 6.25 x 10${}^{-34}g$
• D. 1.438 x 10${}^{-11}g$

Answer 1

The correct option is D 1.438 x 10${}^{-11}g$

1 Curie $=3.7\times {10}^{10}dps$

Assuming, atom of $U^{234}$ shows radioactivity and is at its radioactive state.
Mass of 1 amu $=1.66\times {10}^{-27}kgs$

Mass of 1 curie $=3.7\times {10}^{10}\times 234\times 1.66\times {10}^{-27}\times {10}^{3}gms$

$=1.4372\times {10}^{-11}gms\approx 1.438\times {10}^{-11}gms.$