Does PBr3 has a C3 axis and horizontal symmetry plane
No, PBr3 does not have a C3 axis or a horizontal symmetry plane.
A C3 axis indicates that the molecule has a rotation axis of order 3, meaning that it can be rotated by 120 degrees and still look the same. PBr3 does not have this symmetry because its structure is tetrahedral, meaning it has no special rotational symmetry.
A horizontal symmetry plane indicates that the molecule has a mirror plane that divides it into two equal halves when the molecule is reflected across that plane. PBr3 does not have a horizontal symmetry plane because it is not symmetrical with respect to any plane.
In summary, PBr3 does not possess a C3 axis or a horizontal symmetry plane.