Questions: Assuming all outer atoms are the same element, which molecule is polar?

Assuming all outer atoms are the same element, which molecule is polar? Determine the molecular geometry of each molecule.

1. Trigonal planar
2. Linear
3. Trigonal pyramidal
4. Bent

Analyze the symmetry and dipole moments.

1. Trigonal planar: If all outer atoms are the same, the molecule is nonpolar due to symmetry.
2. Linear: If all outer atoms are the same, the molecule is nonpolar due to symmetry.
3. Trigonal pyramidal: This geometry always results in a polar molecule if the outer atoms are the same since the lone pair of electrons on the central atom creates an asymmetry in the charge distribution.
4. Bent: This geometry always results in a polar molecule if the outer atoms are the same since the lone pairs of electrons on the central atom creates an asymmetry in the charge distribution.

Determine which molecule is polar. The molecules with trigonal pyramidal and bent geometries are polar. Since the question only requires one selection, the trigonal pyramidal molecule will be selected.

\(\boxed{Trigonal \ Pyramidal}\)

\(\boxed{Trigonal \ Pyramidal}\)