Question

The number of three centre two electron bonds in a molecule of diborane is:

• A. zero
• B. two
• C. four
• D. six

Answer 1

The correct option is B two

$B{H}_3$ dimerizes to give diborane $\left(B_2{H}_6\right)$, in which two hydrogen atoms are bridged and four hydrogen atoms are terminal.
In a three centre two electron bond, the two electrons are shared between three atoms.
These types of bonds are also as called banana bonds.