Reactive hydrogen atoms-halogen molecule

This intermediate then can be dehydro-halogenated to give an epoxy functional material. Usually the starting material will contain at least two reactive hydrogen atoms to give a product having at least two epoxy groups per molecule. 

Radioiodination involves the substitution of radioactive iodine atoms for reactive hydrogen sites in target molecules. The process usually involves the action of a strong oxidizing agent to transform iodide ions into a highly reactive electrophilic iodine II compound (typically I2 or a mixed halogen species such as IC1). Formation of this electrophilic species leads to the potential for rapid iodination of aromatic compounds... 

The alkenes are more reactive than the alkanes. For example, alkene molecules undergo addition reactions in which the atoms from halogen molecules or from hydrogen halides bond to the carbon atoms involved in the double bond ... 

As saturated hydrocarbons, the alkanes have the lowest chemical reactivity of organic compounds. However, under certain conditions these compounds can undergo substitution reactions, especially with the halogens. An example of such a reaction is that between an alkane, such as methane, and a halogen, such as chlorine. In this substitution reaction, a chlorine atom replaces a hydrogen atom on the methane molecule. 

Just as the halogens show different reactivities, so too do the hydrogen atoms in a molecule. Consider, for example, the bromination of methylpropane ... 

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