Question

When predicting molecular geometry you must focus on which atom

Options:
a) The most electronegative atom
b) The central atom
c) The atom with the highest atomic mass
d) The atom with the least number of valence electrons

Answer 1

The VSEPR model is used to predict the molecular geometry by focusing on the number of electron pairs around the central atom.

Step-by-step explanation:

We can use the VSEPR model to predict the geometry of most polyatomic molecules and ions by focusing only on the number of electron pairs around the central atom, ignoring all other valence electrons present. According to this model, valence electrons in the Lewis structure form electron groups (regions of electron density), which may consist of a single bond, a double bond, a triple bond, a lone pair of electrons, or even a single unpaired electron, which in the VSEPR model is counted as a lone pair.

Because electrons repel each other electrostatically, the most stable arrangement of electron groups (i.e., the one with the lowest energy) is the one that minimizes repulsions. Groups are positioned around the central atom in a way that produces the molecular structure with the lowest energy.