To determine if a molecule is tetrahedral, we need to analyze its hybridization and VSEPR theory. A molecule is tetrahedral if the central atom has four bond pairs and zero lone pairs, leading to sp³ hybridization.

Step 1: Analyze CF₄
Carbon (C) is the central atom. It has 4 valence electrons. It forms 4 single bonds with 4 fluorine (F) atoms. Number of bond pairs = 4. Number of lone pairs = (4 - 4)/2 = 0. Steric number = 4 + 0 = 4. Hybridization = sp³. Geometry = Tetrahedral.

Step 2: Analyze SF₄
Sulfur (S) is the central atom. It has 6 valence electrons. It forms 4 single bonds with 4 fluorine (F) atoms. Number of bond pairs = 4. Number of lone pairs = (6 - 4)/2 = 1. Steric number = 4 + 1 = 5. Hybridization = sp³d. Geometry = See-saw (derived from trigonal bipyramidal electron geometry).

Step 3: Analyze CH₄
Carbon (C) is the central atom. It has 4 valence electrons. It forms 4 single bonds with 4 hydrogen (H) atoms. Number of bond pairs = 4. Number of lone pairs = (4 - 4)/2 = 0. Steric number = 4 + 0 = 4. Hybridization = sp³. Geometry = Tetrahedral.

Step 4: Analyze SiF₄
Silicon (Si) is the central atom. It has 4 valence electrons. It forms 4 single bonds with 4 fluorine (F) atoms. Number of bond pairs = 4. Number of lone pairs = (4 - 4)/2 = 0. Steric number = 4 + 0 = 4. Hybridization = sp³. Geometry = Tetrahedral.

Based on the analysis, SF₄ has a see-saw geometry, not tetrahedral.

Option Analysis:

• A) CF₄: Central atom C has 4 bond pairs and 0 lone pairs. sp³ hybridized, tetrahedral geometry. Incorrect.
• B) SF₄: Central atom S has 4 bond pairs and 1 lone pair. sp³d hybridized, see-saw geometry. Correct.
• C) CH₄: Central atom C has 4 bond pairs and 0 lone pairs. sp³ hybridized, tetrahedral geometry. Incorrect.
• D) SiF₄: Central atom Si has 4 bond pairs and 0 lone pairs. sp³ hybridized, tetrahedral geometry. Incorrect.

Correct Answer: (B)