Question

Why Boron forms BF4- whereas aluminium forms AlF3- although both boron and aluminium belong same group?

Answer 1

Here boron forms coordinate bond and forms bf4 whereas al forms covalent bond

Answer 2

Hey dear,

● Explaination -
- Aluminium has electronic configuration [Ne] 3s2 3p1.
- Al has vacant d-orbit to fit in more electrons, thus Al can coordinate with 6 F- ions to form [AlF6]3-.
- Boron has electronic configuration [He] 2s2 2p1.
- But B doesnt have d-orbital to fit more electrons and thus coordinates with only 4 F- ions to form [BF4]-.


Hope this help you...