Which of the following is the approximate bond angle between adjacent equatorial atoms in a molecule with square pyramidal geometry?

• A. 109.5^ext{o}
• B. 120^ext{o}
• C. 180^ext{o}
• D. 90^ext{o}

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the molecular geometry. A square pyramidal geometry consists of a central atom bonded to five atoms: four atoms arranged in a square plane (equatorial positions) and one atom above the plane (axial position).
2. Step 2: Identify the positions of the equatorial atoms. The four equatorial atoms lie in the same plane, arranged at the corners of a square around the central atom.
3. Step 3: Recall that in a square planar arrangement, the bond angles between adjacent atoms are 90 degrees because the atoms are positioned at right angles to each other.
4. Step 4: Since the question asks for the bond angle between adjacent equatorial atoms in a square pyramidal molecule, focus on the angles between atoms in the square base, which remain approximately 90 degrees despite the presence of the axial atom.
5. Step 5: Conclude that the approximate bond angle between adjacent equatorial atoms in square pyramidal geometry is 90 degrees.