Hardy-Weinberg equilibrium refers to a model which explains the effect of evolution on the gene pool.
The model is based on the assumptions that if no evolutionary force like genetic drift, natural selection and many other will act on the population and therefore the gene pool (gene frequency and the genotypic frequency) of a populations remains in equilibrium or constant throughout the generations.
PF3Br2 has a trigonal bypiramidal geometry. The three atoms of F will be arranged around the P atom in the same plane and each F-P-F bond will have an angle of 120 degrees. There will be only one Br atom above and beneath the P atom so the bond angle for Br-P-Br will be 180 degrees. Finally, the F−P−Br bond angle will be at 90 degrees.
