The shape of the molecule depends upon the bonded electron pairs
According to VSEPR (Valence Shell Electron Pair Repulsion) theory, the shape of a molecule is determined by the arrangement of its bonded electron pairs. The electrons in the outermost shell of an atom are called valence electrons, and they participate in bonding with other atoms. The arrangement of these bonded electron pairs around the central atom determines the shape of the molecule.

Pair of electrons attract each other in valence shells
In the valence shell of an atom, the pairs of electrons are negatively charged and therefore repel each other due to their like charges. However, they also attract each other due to the positive charge of the nucleus. This attraction helps to hold the electrons in the valence shell and keeps them relatively stable.

The pairs of electrons tend to occupy such positions that minimise repulsions
According to the VSEPR theory, the pairs of electrons in a molecule tend to occupy positions that minimize repulsions between them. This is because the negatively charged electron pairs repel each other, and by arranging themselves in a way that minimizes these repulsions, the molecule can achieve a more stable and energetically favorable state.

The repulsion between electron pairs is dependent on their relative positions. Electron pairs can be either bonding pairs (shared between two atoms) or nonbonding pairs (lone pairs on the central atom). The repulsion between different pairs can be ranked in order of decreasing repulsion as follows:
1. Lone pair - Lone pair repulsion
2. Lone pair - Bonding pair repulsion
3. Bonding pair - Bonding pair repulsion

The pairs of electrons tend to occupy such positions that minimise distances from each other
The VSEPR theory also states that the pairs of electrons in a molecule tend to occupy positions that minimize the distances between them. This is because electrons repel each other, and by arranging themselves in a way that minimizes the distances, the molecule can achieve a more stable and energetically favorable state.

By minimizing both the repulsions and the distances between electron pairs, the molecule can achieve a more stable and energetically favorable arrangement. This leads to the formation of specific molecular shapes, such as linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral, depending on the number of bonding and nonbonding electron pairs around the central atom.

Overall, the VSEPR theory provides a framework for predicting the shapes of molecules based on the arrangement of bonded electron pairs. It helps us understand the three-dimensional structure of molecules and their properties, such as polarity and reactivity.