Aromatic diazonium salts are stable in solution at 273-278 K, but aliphatic diazonium salts decompose at once, mainly because

1. Athe $\mathrm{C}-\mathrm{N}$ bond in the aryl case is longer than in the alkyl case
2. Bthe positive charge on the aryl diazonium ion is delocalised over the benzene ring by resonance
3. Caryl groups have a stronger +I effect than alkyl groups
4. Daryl diazonium ions are bound to chloride by a covalent bond