Which molecular shape is associated with a molecule containing four atoms?

In a molecule containing four atoms, the tetrahedral shape is the most commonly associated geometry. This occurs when a central atom is surrounded by four other atoms or groups, leading to a three-dimensional arrangement where the bond angles between the atoms are approximately 109.5 degrees.

In this tetrahedral arrangement, the four atoms are positioned equidistantly from the central atom, maximizing the distance between them to minimize repulsion. A typical example of this shape is methane (CH₄), where the carbon atom is at the center of the tetrahedron, bonded to four hydrogen atoms.

While trigonal pyramidal is another molecular shape, it specifically occurs when a central atom is bonded to three other atoms and has one lone pair of electrons, which creates a pyramid-like shape with bond angles less than 109.5 degrees, such as in ammonium (NH₃). Therefore, it does not apply to a straightforward arrangement of four atoms.

The planar shape refers to molecules where the atoms lie in a two-dimensional plane and typically occurs with molecules that have double bonds or lack sufficient bonding pairs to create a three-dimensional structure; hence it is not suitable for a tetrahedral arrangement.

Angular or bent shapes arise from molecules with at least one lone pair