Question
Explain why BeH2 molecule has a zero dipole moment although the Be-H bonds are polar?
Solution
BeH2 is a linear molecule in which the two Be-H bonds are oriented in the opposite direction at an angle of 180°. Although the Be-H bonds are polar having the same dipole moment, but due to the linear structure of BeH2, the bond dipoles of the two Be - H bonds cancel each other. Therefore, the resultant dipole moment of BeH2 molecule is zero.
