Draw the 3D structure of the following molecules/ions, specifying the boundary forms of resonance and the resonance hybrid if applicable. Indicate whether the molecule (or ion) is polar or not. d) XeSI4

Suppose that a molecule has four bonding groups and one lone pair on the central atom. Suppose further that the molecule is confined to two dimensions (this is a purely hypothetical assumption for the sake of understanding the principles behind VSEPR theory). Make a sketch of the molecule and estimate the bond angles.

Determine the electron geometry (eg) and molecular geometry (mg) of NO2-, the nitrite anion.

20)       For carbon disulfide (toxic, malodorous, flammable liquid) and selenium disulfide (solid, melting point 111oC, over-the-counter drug used to treat certain types of dermatitis) a) compile their Lewis electron dot formulas     b) identify their electron pair geometry according to the VSEPR theory, c) determine which of these two molecules is polar and which is non-polar and shortly explain why