A sample of sodium-22 (Z= 11) decays to neon-22 (Z 10). The alf-life of this sodium isotope is 2.5 years. The masses of the sodium-22 and neon- 22 atoms are 21.994434 u and 21.991383 u, respectively. The initial mass of the sodium-22 sample is 5 mg. [2 points] What is the radius of the sodium-22 nucleus?