- The force constant for the internuclear force in a hydrogen molecule 1H22 is kʹ = 576 N/m. A hydrogen atom has mass 1.67 x 10-27 kg. Calculate the zero-point vibrational energy for H2 (that is, the vibrational energy the molecule has in the n = 0 ground vibrational level). How does this energy compare in magnitude with the H2 bond energy of -4.48 eV?
- The isotope 57Co decays by electron capture to 57Fe with a half- life of 272 days. The 57Fe nucleus is produced in an excited state, and it almost instantaneously emits gamma rays that we can detect.
- (a) Find the mean lifetime and decay constant for 57Co.
- (b) If the activity of a 57Co radiation source is now 2.00 mCi, how many 57Co nuclei does the source contain?
- (c) What will be the activity after one year?
