Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Types of Chemical Bonds

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert N. Lewis. He developed a model called the Lewis model to explain the type and formation of different bonds. Chemical bonding is central to chemistry; it explains how atoms or ions bond together to form molecules. It explains why some bonds are strong and others are weak, or why one carbon bonds with two oxygens and not three; why water is H2O and not H4O.

Ionic Bonding and Electron Transfer

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.

Phase Transitions: Sublimation and Deposition

Phase Transitions: Sublimation and Deposition

Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...

Chemical Bonds

Chemical Bonds

Atoms participate in a chemical bond formation to acquire a completed valence-shell electron configuration similar to that of the noble gas nearest to it in atomic number. Ionic, covalent, and metallic bonds are some of the important types of chemical bonds. Bond energy and bond length determine the strength of a chemical bond.
Types of Chemical Bonds
An ionic bond is formed due to electrostatic attraction between cations and anions. Often, the ions are formed by the transfer of electrons from...

Types of Chemical Bonds

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert N. Lewis. He developed a model called the Lewis model to explain the type and formation of different bonds. Chemical bonding is central to chemistry; it explains how atoms or ions bond together to form molecules. It explains why some bonds are strong and others are weak, or why one carbon bonds with two oxygens and not three; why water is H2O and not H4O.

Imperfections in Crystal Structure: Stoichiometric Point Defects

Imperfections in Crystal Structure: Stoichiometric Point Defects

Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

A swarm intelligence approach to density function reconstruction from moments using entropy optimization.

Proceedings of the National Academy of Sciences of the United States of America·2026

Same author

Charge-triggered switching mechanism in selenium selector enabling ultralow leakage current.

Nature materials·2026

Same author

Half-Filled Honeycomb Transition-Metal Cyanamide Fe<sub>3</sub>Cr<sub>2</sub>(NCN)<sub>6</sub>.

Inorganic chemistry·2026

Same author

Corresponding orbitals in periodic frozen-density embedding: The case of alkaline-earth subnitrides, Ae2N, by the example of Ba2N.

The Journal of chemical physics·2026

Same author

Cation-Tuned Reaction Mechanisms in Metal Dicyanamide Anodes for Lithium-Ion Batteries with High Reversible Capacity.

ACS nano·2026

Same author

Stabilization of Fully Deprotonated Melaminate Anions (C<sub>3</sub>N<sub>6</sub>)<sup>6-</sup> in M<sub>3</sub>(C<sub>3</sub>N<sub>6</sub>) (M = Cd, Ca).

Journal of the American Chemical Society·2026

Search research articles

Related Experiment Video

Updated: Jun 22, 2026

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV

Published on: December 29, 2016

Reply to Comment on 'Chemical bonding in phase-change chalcogenides'.

P C Müller¹, S R Elliott², R Dronskowski¹

¹Lehrstuhl für Festkörper- and Quantenchemie, Institut für Anorganische Chemie, RWTH Aachen University, D-52056 Aachen, Germany.

Journal of Physics. Condensed Matter : an Institute of Physics Journal

|July 15, 2025

Summary

This summary is machine-generated.

This study refutes claims that phase-change chalcogenide bonds are electron-deficient. Electron-counting rules confirm GeTe bonds are electron-rich, not multicentre, challenging prior interpretations.

Keywords:

chalcogenide materials chemical bonding density functional calculations electron-rich multicentre (‘hypervalent’) bonding phase-change materials quantum theory of atoms in molecules (QTAIM)

More Related Videos

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Published on: August 30, 2024

Related Experiment Videos

Last Updated: Jun 22, 2026

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV

Published on: December 29, 2016

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Published on: August 30, 2024

Area of Science:

Materials Science
Solid-State Chemistry
Computational Chemistry

Background:

Critique of the chemical bonding assignment in phase-change chalcogenides (e.g., GeTe).
Previous work suggested electron-rich ('hypervalent') bonding.
Commenters proposed electron-deficient and multicentre bonding models for (GeTe)1-x(Sb2Te3)x crystals.

Discussion:

Electron-counting rules are applied to reassess the bonding character in GeTe.
Demonstration of inaccuracies in the commenters' electron counting for GeTe.
Explanation of why density-based methods like Quantum Theory of Atoms in Molecules (QTAIM) are insufficient alone for determining bonding character in solids.

Key Insights:

The chemical bonds in GeTe are confirmed to be electron-rich, not electron-deficient or multicentre.
Inaccurate electron counting is the primary reason for the commenters' alternative bonding model.
Over-reliance on density-based calculations without complementary methods can lead to misinterpretations of bonding.

Outlook:

Revisiting bonding analysis in related phase-change materials using rigorous electron-counting methods.
Developing a more comprehensive theoretical framework for understanding bonding in complex chalcogenides.
Guiding future experimental and computational studies on phase-change materials for electronic applications.