Positron emission (β+ decay

Definition

Positron emission (β+ decay) is a type of radioactive decay in which a proton inside a nucleus is converted into a neutron, releasing a positron and a neutrino. It reduces the atomic number by one while keeping the mass number constant.

5 Must Know Facts For Your Next Test

1. The emitted positron has the same mass as an electron but carries a positive charge.
2. Positron emission occurs in proton-rich nuclei where protons outnumber neutrons.
3. The process leads to the formation of a new element with one less proton in its nucleus.
4. A neutrino, which is nearly massless and neutral, is also emitted during positron emission.
5. Common isotopes that undergo β+ decay include carbon-11 and potassium-40.

Review Questions

• What particles are emitted during positron emission?
• How does positron emission affect the atomic number and mass number of an element?
• Why does positron emission occur in certain nuclei?

Related terms

Neutrino: A nearly massless, neutral particle emitted alongside the positron during β+ decay.

Electron Capture: A process where an inner orbital electron is captured by the nucleus, leading to the conversion of a proton into a neutron.

Radioactive Decay: The process by which an unstable atomic nucleus loses energy by emitting radiation.