Radioactivity

Flashcards covering key vocabulary and concepts related to radioactivity.

Radioactivity

The spontaneous emission of particles and energy from an unstable nucleus to become stable.

Ionization

The process where an atom or molecule gains or loses electrons, resulting in a charged particle.

Excitation

The process of raising an electron to a higher energy state without removing it from the atom.

Radionuclides

Atoms involved in radioactivity that undergo radioactive decay.

Radioactive decay

The process of spontaneous emission of particles and energy to achieve stability.

Strong nuclear force

The force that holds protons and neutrons together in the nucleus.

Repulsive force

The force produced by protons due to their positive charge, causing them to repel each other.

Beta emission

The emission of an electron from the nucleus, increasing the atomic number by one.

Alpha emission

The emission of an alpha particle from an unstable nucleus, losing two protons and two neutrons.

Gamma decay

A type of decay that does not change the atomic mass or charge, emitting gamma rays.

Neutrino

An electrically neutral elementary particle that interacts via weak interaction and gravity.

Antineutrino

A particle with opposite signs of lepton number and chirality to a neutrino.

Electron capture

A process where a proton-rich atom captures an electron, resulting in a neutron.

Alpha particle

A particle containing two protons and two neutrons, equivalent to a helium nucleus.

Beta particle

A charged particle emitted from a radioactive nucleus, which can be negatively or positively charged.

Radioisotopes

Isotopes of elements that are unstable and decay to achieve stability.

Auger effect

A phenomenon where filling of an inner shell vacancy accompanies the emission of another electron.

Internal conversion

A non-radioactive process where an excited nucleus causes the emission of an electron.

Particulate radiation

Radiation consisting of alpha and beta particles associated with nuclear decay.

Electromagnetic radiation

Radiation such as gamma rays and X-rays that have no mass and no charge.

Nucleus

The central part of an atom, containing protons and neutrons.

Atomic mass number (A)

The total number of protons and neutrons in the nucleus of an atom.

Atomic number (Z)

The number of protons in the nucleus of an atom, defining the element.

Neutron-rich

Referring to atoms that have more neutrons than protons.

Proton-rich

Referring to atoms that have more protons than neutrons.

Decay mode

The way in which a radioactive nucleus decomposes, such as alpha or beta decay.

Stable nucleus

A nucleus in which the strong nuclear force outweighs the repulsive force between protons.

Unstable nucleus

A nucleus that undergoes decay because the repulsive force exceeds the strong nuclear force.

Radiation exposure

The amount of ionizing radiation that comes in contact with persons or environmental surfaces.

Half-life

The time taken for half of the radioactive nuclei in a sample to decay.

Radon

A radioactive gas that can accumulate in buildings, produced from the decay of uranium.

Cosmic radiation

High-energy radiation from outer space that interacts with the Earth’s atmosphere.

Radiological safety

Practices and regulations to protect people from harmful effects of radiation.

Isobaric transition

A decay process where the number of protons changes but the atomic mass remains the same.

Alpha decay condition

Occurs when A is greater than 150, leading to two protons and two neutrons being emitted.

Beta-plus decay

A type of decay wherein a proton is transformed into a neutron, emitting a positron.

Kinetic energy of alpha particles

Generally between 4 to 7 MeV, allowing them to ionize about 40,000 atoms per centimeter.

Kinetic energy of beta particles

Typically can carry kinetic energy up to 7 MeV.

Photons

Particles of light and other electromagnetic radiation, possessing no mass or charge.

X-rays

A form of electromagnetic radiation produced outside the nucleus, used in imaging.

Gamma rays

Electromagnetic radiation emitted from the nucleus during radioactive decay.

Alpha particle range

Can travel approximately 5 cm in air, but only around 100 µm in soft tissue.

Beta particle range

May traverse 10 to 100 cm of air and approximately 1 to 2 cm of soft tissue.

Electromagnetic radiation characteristics

Include X-rays and gamma rays, both having no mass and traveling at the speed of light.

Particle accelerator

A machine used to artificially produce radioisotopes.

Natural radioisotopes

Radioisotopes that originate from natural processes, like uranium decay.

Chemical elements with atomic number greater than 83

Elements that typically have unstable nuclei and are radioactive.

Decay product

The stable product formed after a radioactive substance undergoes decay.