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Physical Chemistry

Positron

Definition and meaning of Positron in chemistry.

A positron is the antimatter counterpart of a standard electron, possessing the identical mass but carrying a positive electrical charge instead of a negative one.

In more detail

When a positron is emitted during a type of radioactive decay known as beta plus decay, a proton in the nucleus is converted into a neutron. Because it is an antimatter particle, a positron will undergo instant annihilation when it collides with a standard electron. This collision permanently destroys both particles and converts their entire mass into high-energy gamma rays according to mass-energy equivalence. Positron emission is widely utilized in medical imaging techniques such as PET scans to observe metabolic processes occurring inside the human body.

Key facts

FieldPhysical Chemistry
Charge+1 elementary charge
Antiparticle ofElectron
Annihilation ProductGamma rays
Example

The radioactive isotope carbon-11 undergoes beta plus decay to become boron-11, releasing a positron and a neutrino in the process.

Frequently asked questions

What happens when a positron meets an electron?

They annihilate each other instantly, converting their entire mass into pure energy in the form of two gamma ray photons.

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