Cobalt-60 is a strong gamma emitter that has a half-life of 5.26 yr.The cobalt-60 in a radiotherapy unit must be replaced when its radioactivity falls to of the original sample.If an original sample was purchased in June 2010, when will it be necessary to replace the cobalt-60?
Chapter 9 - Covalent Bonding: Orbitals 9.1 Hybridization and the Localized Electron Model A. Hybridization 1. The mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal energies B. Hybrid Orbitals 1. Orbitals of equal energy produced by the combination of two or more orbitals on the same atom C. Evidence for hybridization of carbon - Methane and sp 3 1. Four bonds of equal length and strength Carbon's isolatedconfiguration Carbon's hybridized configuration 2. Four effective pairs of electrons surround the carbon 3. "Whenever a set of equivalent tetrahedral atomic or