Problem 7 - Chemistry The Central Science

Question

The orbital diagram that follows presents the final step in the formation of hybrid orbitals by a silicon atom. What type of hybrid orbital is produced in this hybridization? [Section 9.5\(]\)

Step-by-Step Solution

Answer

The type of hybrid orbital produced in the hybridization of a silicon atom is the sp³ hybrid orbital. This is because silicon combines one 3s and three 3p orbitals, obtaining a total of four orbitals participating in the hybridization process.

Step 1: Determine the electron configuration of silicon

First, we need to determine the electron configuration of a silicon (Si) atom. Silicon has 14 electrons. Its electron configuration is: 1s² 2s² 2p⁶ 3s² 3p²

Step 2: Identify the valence electron orbitals

Next, let's identify the orbitals containing the valence electrons. In the electron configuration we found, the valence electrons are in the 3s and 3p orbitals. The valence electron configuration for silicon is: 3s² 3p²

Step 3: Determine the orbitals participating in the hybridization

We need to figure out which orbitals are involved in the hybridization process. Since silicon has 4 valence electrons (2 in 3s and 2 in 3p), it needs 4 orbitals to accommodate these electrons. Silicon merges one 3s and three 3p orbitals in the hybridization process.

Step 4: Identify the type of hybrid orbitals formed

Since silicon combines one 3s and three 3p orbitals, we have a total of four orbitals participating in the hybridization process. Therefore, the type of hybrid orbitals formed is sp³ hybrid orbitals. In conclusion, the type of hybrid orbital produced in the hybridization of a silicon atom is the sp³ hybrid orbital.

Key Concepts

Understanding Orbital Diagram

An orbital diagram visually represents how electrons are distributed within an atom’s orbitals. It involves arrows indicating electrons and boxes representing the orbitals.

• Each arrow represents an electron, and the direction of the arrow shows the electron spin, with each orbital holding up to two electrons with opposite spins.
• Silicon's configuration, as described, includes arrows up and down in the 3s orbital and two arrows in separate 3p sub-orbitals.
• The combination of these orbitals during hybridization influences the shape and bonding characteristics of the silicon atom in compounds.

An orbital diagram not only shows distribution but also gives clues about how these electrons may participate in chemical bonding.

Decoding Electron Configuration

Electron configuration details how electrons occupy the various energy levels and subshells within an atom. For silicon:

• The electron configuration 1s² 2s² 2p⁶ 3s² 3p² indicates 14 electrons distributed over the primary energy levels and subshells.
• The 1s, 2s, and 2p orbitals are filled completely, making them part of the core electrons.
• The electrons in the 3s and 3p are considered valence electrons since they participate in bonding.

This configuration helps predict how an atom like silicon can form bonds through hybridization, merging its orbitals for stronger, effective bonds.

Valence Electrons and Their Role

Valence electrons are the outermost electrons of an atom and are crucial in determining how atoms interact with each other.

• For silicon, the valence electron configuration is 3s² 3p², indicating four valence electrons in the third shell.
• The 3s and 3p electrons mingle through hybridization, forming sp³ orbitals, enabling silicon to form four bonds typically seen in molecules like silicon dioxide (SiO₂).
• These electrons dictate the chemical reactivity and properties of silicon, highlighting their importance in molecular geometry and bonding properties.

Understanding valence electrons provides insight into why atoms bond the way they do, playing a vital role in the structural formation of compounds.