What is the hybridisation states of the central atoms of the followings two compounds ??? predict the structure …...

the compounds are

1. N(CH₃)₃
2. N(SiH₃)₃

In trimethyl ammine, the hybridisation is sp3 with a lone pair, but in case of trisilyl ammine, due to the presence of vacant d orbital in silicon, it accepts the lone pair of electrons from nitrogen making the lone pair unavailable due to which it`s hybridisation becomes sp2, trigonal planar geometry, it is p pi - d pi back bonding in case of trisilyl ammine