Answer: The shape of boron in borohydride ion
is tetrahedral and in boron trifluoride
is trigonal planar.
Explanation: Formula used
where, V = number of valence electrons present in central atom
N = number of monovalent atoms bonded to central atom
C = charge of cation
A = charge of anion
1.
The number of electron pairs is 4 that means the hybridization will be
and the electronic geometry of the molecule will be tetrahedral.
2.
The number of electron pairs is 3 that means the hybridization will be
and the electronic geometry of the molecule will be trigonal planar.