Electron configuration halogen family elements

Iodine (I), atomic mass 129.9044, atomic number 53, is a non-metallic element of the halogen family. The electronic configuration of the iodine atom is [Kr]4d °5s 5p. The relative atomic mass of the only stable isotope of iodine is 127. There are 22 artificial isotopes with masses between 117 and 139, and fourteen of these yield significant radiation, I through I and I through "1. The half-lives of the isotopes vary between 86 s ( I) and 1.6x10 years ( l). l is a product of the fission of U with slow neutrons. The most important isotopes... 

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