Ch.9 - Molecular Geometry and Bonding Theories

Brown - Chemistry: The Central Science 14th Edition

Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook

Brown 14th Edition

Ch.9 - Molecular Geometry and Bonding Theories

Problem 6a

Chapter 9, Problem 6a

The orbital diagram that follows presents the final step in the formation of hybrid orbitals by a silicon atom. (a) Which of the following best describes what took place before the step pictured in the diagram: (i) Two 3p electrons became unpaired, (ii) An electron was promoted from the 2p orbital to the 3s orbital, or (iii) An electron was promoted from the 3s orbital to the 3p orbital?

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

Verified step by step guidance

Identify the initial electron configuration of silicon: 1s^2 2s^2 2p^6 3s^2 3p^2.

Observe the given orbital diagram, which shows the 3s and 3p orbitals.

Note that in the initial state, the 3s orbital has two electrons and the 3p orbitals have two electrons, with one electron in each of two 3p orbitals.

Recognize that the final state shows the 3s orbital empty and three 3p orbitals each with one electron.

Conclude that an electron was promoted from the 3s orbital to the 3p orbital, resulting in the configuration shown in the final state.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Hybridization

Hybridization is the process by which atomic orbitals mix to form new hybrid orbitals, which are used to describe the bonding in molecules. In the case of silicon, the 3s and 3p orbitals combine to create four equivalent sp3 hybrid orbitals, allowing for the formation of four covalent bonds. Understanding hybridization is crucial for predicting molecular geometry and bonding properties.

Electron Promotion

Electron promotion refers to the process where an electron from a lower energy orbital is excited to a higher energy orbital. This is often necessary for hybridization to occur, as it allows for the formation of unpaired electrons in the orbitals involved in bonding. In silicon, promoting an electron from the 3s to the 3p orbital enables the formation of the required unpaired electrons for hybridization.

Orbital Diagrams

Orbital diagrams visually represent the distribution of electrons in an atom's orbitals. Each box represents an orbital, and arrows indicate the presence of electrons, with their spins. These diagrams help in understanding the electron configuration and the process of hybridization, as they illustrate how electrons are arranged before and after hybridization occurs.

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Guided course

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Electron Orbital Diagrams

Related Practice

Textbook Question

For each molecule (a)–(f), indicate how many different electron-domain geometries are consistent with the molecular geometry shown. a.

In the hydrocarbon (b) How many s bonds are there in the molecule?

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Textbook Question

The following plot shows the potential energy of two Cl atoms as a function of the distance between them. (c) If the Cl₂ molecule is compressed under higher and higher pressure, does the Cl–Cl bond become stronger or weaker?

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Textbook Question

In the hydrocarbon

(a) What is the hybridization at each carbon atom in the molecule?

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Textbook Question

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

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