What is the bond angle for a molecule with two bonded pairs and two lone pairs of electrons?

For a molecule with two bonded pairs and two lone pairs of electrons, the molecular geometry is based on the tetrahedral arrangement of electron pairs, which includes the bonded and lone pairs. In this case, the shape is classified as bent or angular due to the presence of the two lone pairs.

In a perfect tetrahedral geometry, the bond angles would be approximately 109.5°. However, the presence of lone pairs influences the bond angles because lone pairs occupy more space than bonded pairs, resulting in repulsion that compresses the angles between the bonded pairs.

As a result, the bond angle in a bent molecular shape with two lone pairs is less than the tetrahedral angle, typically around 104.5°. This specific angle reflects the adjustment due to the lone pairs' repulsion, which is why the correct answer is 104.5°.

Other options, such as 120° or 90°, do not apply to this molecular configuration, as they correspond to different shapes and degrees of electron pair repulsion in other types of geometries. The angle of 180° would imply a linear arrangement, which is also not relevant here given the presence of both bonded and lone pairs.