Browse Definitions:
Definition

matter

Matter is a substance that has inertia and occupies physical space. According to modern physics, matter consists of various types of particles, each with mass and size.

The most familiar examples of material particles are the electron, the proton and the neutron. Combinations of these particles form atoms. There are more than 100 different kinds of atoms, each kind constituting a unique chemical element. A combination of atoms forms a molecule. Atoms and/or molecules can join together to form a compound.

Matter can exist in several states, also called phases. The three most common states are known as solid, liquid and gas. A single element or compound of matter might exist in more than one of the three states, depending on the temperature and pressure. Less familiar states of matter include plasma, foam and Bose-Einstein condensate. These states occur under special conditions.

Different kinds of matter can combine to form substances that may not resemble any of the original ingredients. For example, hydrogen (a gaseous element) and oxygen (another gaseous element) combine to form water (a liquid compound at room temperature). The process of such combination is called a chemical reaction. A chemical reaction involves interactions between the electrons of the atoms, but does not affect the nuclei of the atoms.

In some situations, matter is converted into energy by atomic reactions, also known as nuclear reactions. This type of reaction is fundamentally different from the chemical reaction because it involves changes in the nuclei of atoms. The most common example of an atomic reaction is the hydrogen fusion that occurs inside the sun. The immense pressure inside the sun, and inside other stars, forces atoms of hydrogen together to form atoms of helium. In this process, some of the mass is converted to energy according to the formula

E = mc 2

where E is the energy in joules, m is the mass in kilograms, and c is the speed of light, which is approximately 2.99792 x 10 8 meters per second in a vacuum.

In recent years, scientists have confirmed the existence of a substance called antimatter. The electron has an antiparticle twin called a positron, with equal mass but opposite electric charge. Similarly, the proton has an antimatter twin called an antiproton, and the neutron has an antimatter twin called an antineutron. If a particle of matter encounters its antiparticle, both are converted entirely to energy according to the above formula, where m is the combined mass of the particle and the antiparticle. Small amounts of antimatter have been isolated in laboratory conditions, but no one has yet succeeded in creating a controlled a matter/antimatter reaction, or even an uncontrolled reaction of significant size.

This was last updated in May 2016

Continue Reading About matter

Join the conversation

1 comment

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

what is love
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • cyborg anthropologist

    A cyborg anthropologist is an individual who studies the interaction between humans and technology, observing how technology can ...

  • RegTech

    RegTech, or regulatory technology, is a term used to describe technology that is used to help streamline the process of ...

  • conduct risk

    Conduct risk is the prospect of financial loss to an organization that is caused by the actions of an organization's ...

SearchSecurity

  • application whitelisting

    Application whitelisting is the practice of identifying applications that have been deemed safe for execution and restricting all...

  • security

    Security, in information technology (IT), is the defense of digital information and IT assets against internal and external, ...

  • insider threat

    An insider threat is a malicious hacker (also called a cracker or a black hat) who is an employee or officer of a business, ...

SearchHealthIT

  • HIPAA Privacy Rule

    The Standards for Privacy of Individually Identifiable Health Information, commonly known as the HIPAA Privacy Rule, establishes ...

  • HIPAA business associate agreement (BAA)

    Under the U.S. Health Insurance Portability and Accountability Act of 1996, a HIPAA business associate agreement (BAA) is a ...

  • telemedicine

    Telemedicine is the remote delivery of healthcare services, such as health assessments or consultations, over the ...

SearchDisasterRecovery

  • data recovery

    Data recovery restores data that has been lost, accidentally deleted, corrupted or made inaccessible. Learn how data recovery ...

  • disaster recovery plan (DRP)

    A company's disaster recovery policy is enhanced with a documented DR plan that formulates strategies, and outlines preparation ...

  • fault-tolerant

    Systems with integrated fault tolerance are designed to withstand multiple hardware failures to ensure continuous availability.

SearchStorage

  • data deduplication

    Deduplication retains one unique data instance to reduce storage and bandwidth consumed by remote backups, replication and ...

  • byte

    In most computer systems, a byte is a unit of data that is eight binary digits long. Bytes are often used to represent a ...

  • Secure Digital card (SD card)

    SD cards use flash memory to provide nonvolatile storage. They are more rugged than traditional storage media and are used in ...

SearchSolidStateStorage

  • flash file system

    Flash file systems are designed specifically for memory devices. A well-designed flash device and flash file system ensure ...

  • IOPS (input/output operations per second)

    IOPS measures the maximum number of reads and writes to non-contiguous storage. It is not an actual benchmark since vendor ...

  • eMMC (embedded MultiMediaCard)

    An embedded MultiMediaCard (eMMC) is a small storage device made up of NAND flash memory and a simple storage controller.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close