Question

Which of the following hybridizations does the Be atom in BeH \(_{2}\) assume? A. \(s p\) B. \(s p^{2}\) C. \(s p^{3}\) D. \(s p^{3} d\)

Short answer

The Be atom in BeH_{2} assumes sp hybridization.

Step-by-step solution

- Understanding the molecule structure

The molecule BeH _{2} is a simple linear molecule with beryllium in the center bonded to two hydrogen atoms.

- Determine the electron geometry

Beryllium in BeH _{2} has two bonding pairs of electrons and no lone pairs. The ideal electron-pair geometry for this configuration is linear.

- Count the number of hybrid orbitals required

For a linear molecule, beryllium needs 2 hybrid orbitals to form two bonds. This corresponds to sp hybridization, as it involves one s orbital and one p orbital combining.

- Match with the given options

Comparing with the given options: A. sp, B. sp^{2}, C. sp^{3}, D. sp^{3}d - the correct match is A. sp.

Key concepts

Linear Molecular Geometry

In order to fully grasp the structure of BeH₂, it is important to understand the concept of linear molecular geometry. A molecule is said to have a linear geometry when all its constituent atoms are arranged in a straight line. This is a common arrangement seen in molecules with two bonding pairs and no lone pairs on the central atom.

Taking our example of BeH₂, Beryllium (Be) is the central atom and has two hydrogen (H) atoms bonded to it. There are no lone pairs on Beryllium, which results in a 180° angle between the bonded atoms, forming a straight line. This simple structure is characteristic of linear molecular geometry.

Understanding this geometry is essential as it directly affects the types of hybridization the central atom will undergo.

sp Hybridization

The concept of sp hybridization can seem tricky but it is quite logical when broken down into steps. Hybridization involves the mixing of atomic orbitals to form new hybrid orbitals, which are used to form bonds with other atoms.

In BeH₂, Beryllium needs to form two bonds to two hydrogen atoms. For this, Beryllium undergoes sp hybridization. Here’s a simple breakdown of how this happens:

• Beryllium has an electron configuration of 1s² 2s².
• To bond effectively with two hydrogen atoms, it needs two equivalent orbitals.
• One 2s orbital and one 2p orbital mix to form two sp hybrid orbitals.

Each of these new sp hybrid orbitals will contain one electron ready to pair up with an electron from a hydrogen atom to form a bond, resulting in a linear arrangement. The term