According to Valence Shell Electron Pair Repulsion (VSEPR) Theory, what is the steric number for BF_3?

• A. 6
• B. 3
• C. 2
• D. 4

Answer: (B)

Verified step by step guidance

1. Identify the central atom in the molecule BF_3, which is boron (B).
2. Determine the number of atoms directly bonded to the central atom. In BF_3, boron is bonded to three fluorine atoms.
3. Count the number of lone pairs of electrons on the central atom. Boron in BF_3 has no lone pairs because it forms three single bonds and has an incomplete octet.
4. Calculate the steric number using the formula: \(\text{Steric Number} = \text{Number of bonded atoms} + \text{Number of lone pairs on central atom}\).
5. Apply the values: \(\text{Steric Number} = 3 + 0 = 3\). This steric number corresponds to the electron pair geometry around the central atom.