Background Energy Data for Halogen Atoms

The thermochemistry of the halo n atoms (Table 1) is highly important in determining their reactivity. For example, abstraction of hydrogen atoms by F and Cl is exoergic, and the relevant reactions therefore possess low activation barriers. The converse is true for Br and and the room-temperature chemistry of I in particular, is actually very limited because of the availability of few exo gic reaction paths. 

ProductioD of Atoms.—Ground-state halogen atoms may be produced by direct 

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