Question

If a central atom of a molecule only has two electron domains, what is the only possible shape the molecule can have?
(A) Linear
(B) Bent
(C) Pyramidal
(D) Opposite

Answer 1

Hint: The number of lone pairs or chemical bond locations that surround an atom is known as its electron domain. It denotes the number of places where electrons are expected to be found. You can predict the geometry of a molecule by knowing the electron domain of each atom. This is due to the fact that electrons are distributed around an atom to reduce repulsion between them.

Complete answer:
According to VSEPR theory, such a structure has a bent shape.
Consider the following example:
Instead of being a linear molecule, water is a bent molecule. The electronegative nature of the oxygen atom accounts for this bent shape. The electronegativity of oxygen causes the molecule to have a dipole moment.
Explanation: There are four pairs of electrons in the central oxygen atom. In single covalent bonds with hydrogen atoms, two pairs are shared. The other two pairs don't have any other atoms in them (non-bonding pair).
The valence shell electron-pair repulsion theory (VSEPR theory) allows us to predict a molecule's molecular structure, including approximate bond angles around a central atom, based on its Lewis structure's number of bonds and lone electron pairs. The VSEPR model assumes that electron pairs in a central atom's valence shell will arrange themselves in such a way that their repulsions are minimised while their distance is maximised. The electrons in a central atom's valence shell form either bonding pairs or lone pairs, which are located primarily between bonded atoms. When the various regions of high electron density take positions as far apart as possible, the electrostatic repulsion of these electrons is reduced.
Hence, Option (B) is correct.

Note:
The VSEPR theory predicts the arrangement of electron pairs around each central atom, as well as the correct arrangement of atoms in a molecule, in most cases. However, we must keep in mind that the theory only considers electron-pair repulsions. Other interactions, such as nuclear-nuclear repulsions and nuclear-electron attractions, are also important in determining the final arrangement of atoms in a molecular structure.