# How do you draw the Lewis structure for SeO2. What is the electron geometry around the central atom?

Lorena

Here are the steps I follow when drawing a Lewis structure.

1. Decide which is the central atom in the structure.

That will normally be the least electronegative atom (Se).

1. Draw a skeleton structure in which the other atoms are single-bonded to the central atom:

O-Se-O

1. Draw a trial structure by putting electron pairs around every atom until each gets an octet.

In this editor, I will have to write it as

:..O−..Se−..O:
ll..     ..        ..

1. Count the valence eletrons in your trial structure (20).
2. Now count the valence electrons you actually have available.

1 Se + 2 O = 1×6 + 2×6 = 18.

The trial structure has two extra electrons.

1. Draw a new trial structure, this time inserting one double bond for each extra pair of electrons:

O=Se-O and O-Se=O

1. As before, add valence electrons to give each atom an octet:

:..O=Se−..O:
..       ..      ..

and

:..O−Se=..O:
..  ..    ..

1. Calculate the formal charge on each atom.

:..O=+1Se−..O:-1
..  ..    ..

We say that these are resonance structures of SeO2.

The actual structure of SeO2 is a resonance hybrid of all three structures.

Example1:

What is the purpose of Lewis structures?

The purpose of Lewis structures is to provide a simple way for chemists to represent molecules that allows reasonable predictions to be made about the structure and properties of the actual molecules. A hydrogen atom has one valence electron. A fluoride atom has seven valence electrons.

Example2:

Why are Lewis structures important?

Second, the importance of Lewis structure. In fact, Lewis structures are very important for predicting geometry, polarity and reactivity of inorganic compounds. Third, how to draw Lewis structure. For individual atoms, the Lewis structure is drawn by placing a dot around the atom for each valence electron available.

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