Haloarenes are less reactive than haloalkanes towards nucleophilic substitution.

Solution

Chemistry ma’am · 4 steps

In a haloarene the C–X bond is partly a double bond, so the nucleophile struggles to push the halogen out.

1. Resonance. A lone pair on the halogen delocalises into the benzene ring. This gives the C–X bond partial double bond character, which a haloalkane does not have.
2. Shorter, stronger bond. The carbon bearing X in a haloarene is sp², which holds bonding electrons more tightly than the sp³ carbon of a haloalkane. The C–Cl bond is 169 pm in chlorobenzene against 177 pm in chloromethane, so it is harder to break.
3. Both paths blocked. An S_N1 route would need a phenyl cation, which resonance cannot stabilise, so it barely forms. An S_N2 backside attack is blocked by the ring itself and repelled by its electron-rich π cloud.
4. So. Haloarenes are much less reactive than haloalkanes towards nucleophilic substitution, so the statement is true.

The idea to keep. Halogen on a ring means resonance, partial double bond and an sp² carbon. That bond resists nucleophiles unless you add ortho/para -NO₂ groups or use harsh conditions.

Answer from the NTA final answer key. Solution by PrepWiser.