`S_(N)2` reaction occurs with `"inversion of configuration" // "racemisation"`.

Explanation

To determine whether an \( S_N2 \) reaction results in "inversion of configuration" or "racemization," we can analyze the mechanisms of \( S_N2 \) and \( S_N1 \) reactions step by step.

### Step 1: Understanding \( S_N2 \) Mechanism
In an \( S_N2 \) reaction, a nucleophile attacks the electrophilic carbon atom from the opposite side of the leaving group. This backside attack leads to the simultaneous formation of a new bond and the breaking of the old bond.

**Hint:** Remember that the nucleophile approaches the carbon atom from the side opposite to the leaving group.

### Step 2: Inversion of Configuration
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