Question

Identify compounds in which the central atom has incomplete octet.
$B{F}_3,AlC{l}_3,GaC{l}_2,MgC{l}_2,BeC{l}_2$

Answer 1

1. $AlC{l}_3$
   
2. $BeC{l}_2$ ,both have incomplete octet that's why they form dimer.
3. $B{F}_3$ ,back bond is found in the $B{F}_3$ .