In a tetrahedral molecule, the four electron pairs surrounding the central atom are arranged in a three-dimensional space in a way that minimizes repulsion between them. This arrangement results in a symmetrical distribution of charge around the central atom and creates a nonpolar molecule.

In the case of CH4, the four hydrogen atoms are arranged tetrahedrally around the central carbon atom. The electronegativity of carbon and hydrogen atoms is almost the same, so the electron pairs are shared equally between them. This results in a symmetrical distribution of charge and no net polarity in the CH4 molecule.