Questions: Number of electron groups Bond angle Outer atoms/Lone pairs Shape 2 ? 2 / 0 ? 3 ? 3 / 0 trigonal planar (planar triangular) 4 2 / 1 ? 4 / 0 tetrahedral bond angle in a two electron group molecule: square The shape of a two electron group molecule is bond angle in a three electron group molecule: square The shape of a three electron group molecule with two outer atoms and one lone pair is

Solution Steps

For a molecule with two electron groups, the bond angle is typically \(180^\circ\). This is because the electron groups are arranged linearly to minimize repulsion, resulting in a linear shape.

For a molecule with three electron groups and no lone pairs, the bond angle is typically \(120^\circ\). This is characteristic of a trigonal planar shape, where the electron groups are evenly distributed around the central atom.

For a molecule with four electron groups, two of which are outer atoms and one is a lone pair, the shape is bent or angular. This is because the lone pair occupies more space and pushes the two outer atoms closer together, resulting in a bond angle slightly less than \(109.5^\circ\), which is typical for a tetrahedral arrangement.

Final Answer