Answer:
A trigonal pyramid is a tetrahedron with one vacant vertex.
Explanation:
How does a trigonal pyramid differ from a tetrahedron so far as molecular geometry is concerned?
Bond angles in the tetrahedral molecule are 120°, while those for trigonal pyramid are 109.5°. FALSE. Bond angles in the tetrahedral are 109.5°, while those for the trigonal pyramid are slightly lower than 109.5° due to the repulsion of the unshared pair of electrons on the central atom.
A trigonal pyramid is a tetrahedron with two vacant vertex. FALSE.
A trigonal pyramid is a tetrahedron with one vacant vertex. TRUE. This is the geometry of NH₃, in which the central atom is bonded to 3 atoms and has 1 unshared pair of electrons.
Bond angles in the tetrahedral molecule are 109.5°, while those for trigonal pyramid are 120°. FALSE.
A tetrahedron has a square base, while the base of a trigonal pyramid is a triangle. FALSE. Both have a triangular base.
