The geometry of the molecule actually determines number of electron pairs on the central atom. The electron pairs will be arranged in such a way to minimize the repulsion and therefore, have the lowest possible energy.
trigonal bipyramidal
Br-. Bromine will grab an electron to make itself more stable, which makes it a negative ion.
This neutral (no charge) molecule has a bent linear geometry or an angular geometry, based on its Lewis structure, ::N=N=N:. (with a total of 15 valence electrons), with the dots representing electrons in non-bonding pairs, except for the one unpaired electron. It has a linear molecular geometry, because, as shown, it has only two electron domains or regions (around its central atom), which are more stably situated 180 degrees away from each other (according to the VSEPR theory). Note: The person asking this question seems to be asking for N3 with no charge on it; but I suspect s/he meant to ask for the azide ion, (N3)-, which would have 16 valence electrons, and that would also give a linear molecular structure.
A positive ion or an atom that has been stripped off one electron.
carbonate ion is having trigonal planar geometry
The electron pairs in an ammonium ion are disposed along the four lines from the center of a tetrahedron to the four corners of the tetrahedron, with the nitrogen atom at the center of the tetrahedron.
The molecular geometry of the AsO2- ion is bent (because of the lone electron pair with the central arsenic atom, making the O-As-O bond angle very obtuse) but its electron domain geometry is trigonal planar because there are three domains, with a 120 deg. angle between them.
Its actually electron pair repulsion. Its the principle that electron pairs around a central atom tend to orient themselves as far apart as possible. Electron pair repulsion is used to predict the geometry of a molecule or a polyatomic ion.
sp2, trigonal planar, bent
a phosphate ion is PO43-
PO43-
Think of the sulfite ion as a molecule with its geometry and dipole moment AND a net charge. The electron pair geometry is tetrahedral and the molecular geometry is trigonal pyramidal and because of its asymmetrical shape and polar bonds, sulfite has a net dipole moment (2.04D ). The ion is polar.
ICl4-'s electron domain geometry is octahedral.
The phosphate ion PO43-
A Lewis acid accepts an electron pair.
The phosphate ion is PO43-