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

To draw the Lewis structure for selenium dioxide (SeO₂), follow these steps:

Step-by-Step Guide to Drawing the Lewis Structure

• Count the Valence Electrons: Selenium (Se) has 6 valence electrons, and each oxygen (O) has 6. Therefore, SeO₂ has a total of 6 + (2 x 6) = 18 valence electrons.
• Determine the Central Atom: Selenium is less electronegative than oxygen, so it will be the central atom.
• Connect the Atoms: Place the two oxygen atoms around the selenium atom and connect them with single bonds. This uses 4 electrons (2 for each bond).
• Distribute Remaining Electrons: After forming the bonds, you have 14 electrons left. Place 6 electrons (3 lone pairs) around each oxygen to satisfy their octets.
• Complete the Octet for Selenium: Selenium can expand its octet. Form double bonds between selenium and each oxygen by sharing one lone pair from each oxygen. This uses 4 electrons, leaving 6 electrons around selenium.

The final structure shows selenium with two double bonds to oxygen atoms, fulfilling the octet rule for all involved atoms.

Electron Geometry

The electron geometry around the central selenium atom in SeO₂ is trigonal planar. This is due to the arrangement of the double bonds and the absence of lone pairs on the selenium atom, leading to a symmetrical shape.