Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Network Covalent Solids02:18

Network Covalent Solids

Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
Ferromagnetism01:31

Ferromagnetism

Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
Work01:14

Work

Work is a fundamental concept of mechanical engineering and has many applications. Understanding how work is calculated and the different types of work can help us better understand physical processes and provide insights into complex problems.
Work is defined as the result of a force acting on an object, causing it to move along the line of action of force. It is also defined as the process of transferring energy through the application of force on an object, resulting in its displacement.
Softwoods and Hardwoods01:28

Softwoods and Hardwoods

Softwoods and hardwoods, derived from different types of trees, are distinguished by their leaf structures and cellular compositions, each serving unique purposes in construction and manufacturing. Softwoods come from cone-bearing trees with needle-like leaves and are predominantly composed of longitudinal cells called tracheids and a smaller proportion of radial cells known as rays. Due to their cellular structure, softwoods are commonly used in construction for structural frames, sheathing,...
Toughness and Hardness of Aggregate01:22

Toughness and Hardness of Aggregate

Toughness and hardness are critical properties of aggregate materials used in concrete, particularly on pavement surfaces and industrial flooring subjected to heavy loads. Toughness is defined as the aggregate's resistance to failure by impact and is measured by the aggregate impact value (AIV). For this, the aggregate impact value test is performed, wherein the impact is delivered by a standard hammer, which falls freely under its own weight onto the aggregates. The aggregates fragment in the...
Mechanical Characteristics of Steel01:18

Mechanical Characteristics of Steel

The mechanical characteristics of steel are assessed through various tests that evaluate its strength, toughness, and flexibility. These tests include tension, torsion, impact, bending, and hardness assessments, each providing crucial information about steel's suitability for specific applications.
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used to...

You might also read

Related Articles

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

Sort by
Same author

Strength of spider silk.

Science (New York, N.Y.)·1996
Same author

Metallic glasses.

Science (New York, N.Y.)·1980
Same journal

Erratum for the Research Article "Detecting supramolecular organic nanoparticles during heat wave".

Science (New York, N.Y.)·2026
Same journal

Local signals, systemic decline.

Science (New York, N.Y.)·2026
Same journal

The mechanics of liver regeneration.

Science (New York, N.Y.)·2026
Same journal

Computing in a memory with physics.

Science (New York, N.Y.)·2026
Same journal

Retraction.

Science (New York, N.Y.)·2026
Same journal

Making time.

Science (New York, N.Y.)·2026
See all related articles

Related Experiment Video

Updated: Jul 7, 2026

Quantitative Hardness Measurement by Instrumented AFM-indentation
08:21

Quantitative Hardness Measurement by Instrumented AFM-indentation

Published on: November 22, 2016

Why silicon is hard.

J J Gilman

    Science (New York, N.Y.)
    |September 10, 1993
    PubMed
    Summary
    This summary is machine-generated.

    Covalent solids like silicon are brittle due to limited dislocation movement. This brittleness is explained by an atomic process analogous to chemical substitution, revealing why these materials resist deformation.

    More Related Videos

    Determining the Mechanical Strength of Ultra-Fine-Grained Metals
    05:04

    Determining the Mechanical Strength of Ultra-Fine-Grained Metals

    Published on: November 22, 2021

    Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models
    06:16

    Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models

    Published on: April 26, 2024

    Related Experiment Videos

    Last Updated: Jul 7, 2026

    Quantitative Hardness Measurement by Instrumented AFM-indentation
    08:21

    Quantitative Hardness Measurement by Instrumented AFM-indentation

    Published on: November 22, 2016

    Determining the Mechanical Strength of Ultra-Fine-Grained Metals
    05:04

    Determining the Mechanical Strength of Ultra-Fine-Grained Metals

    Published on: November 22, 2021

    Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models
    06:16

    Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models

    Published on: April 26, 2024

    Area of Science:

    • Materials Science
    • Solid-State Physics
    • Chemical Physics

    Background:

    • Covalent solids, such as silicon, exhibit hardness and brittleness, unlike metals and ionic salts.
    • Dislocation motion in covalent solids is restricted, occurring only at elevated temperatures.
    • A clear explanation for this phenomenon has been elusive, despite its significance in materials mechanics.

    Purpose of the Study:

    • To provide a satisfactory explanation for the brittleness of covalent solids.
    • To elucidate the atomic-level mechanisms governing dislocation movement in these materials.
    • To link the mechanical properties of covalent solids to their bonding characteristics.

    Main Methods:

    • Analogy between dislocation movement and chemical substitution reactions.
    • Utilizing correlation diagrams for atomic process analysis.
    • Investigating the role of atomic bonding symmetry in material deformation.

    Main Results:

    • The critical atomic process for brittleness is analogous to a chemical substitution reaction.
    • Analysis reveals a high resistive stress and high activation energy for dislocation motion.
    • Dislocation kink movement disrupts atomic bonding symmetry, a process that is energetically unfavorable.

    Conclusions:

    • The observed brittleness of covalent solids is fundamentally linked to an atomic substitution-like process.
    • High resistive stress and activation energy are direct consequences of this process.
    • The breaking of atomic bonding symmetry during dislocation motion explains the material's resistance to deformation.