The SN2 reaction - A Nucleophilic Substitution in which the Rate Determining Step involves 2 components.

-SN2 reactions are bimolecular with simultaneous bond-making and bond-breaking steps.
-SN2 reactions do not proceed via an intermediate.
-SN2 reactions give inversion of stereochemistry at the reaction centre.
-Steric effects are particularly important in SN2 reactions.

For example:

 
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