Nuclear Chemistry Flashcards

Vocabulary flashcards covering the key concepts of nuclear chemistry, including radioactive decay, fission, fusion, and nuclear technologies.

Nuclear radiation

A form of ionizing radiation that results from the changes in nuclei of atoms.

Radioactivity

The emission of energetic particles and photons from unstable atomic nuclei.

Radioisotopes

Elements that emit radioactivity.

Nucleons

Protons and neutrons that make up the nucleus.

Strong nuclear force

The force that overcomes the repulsion between protons and holds the nucleons together within the nucleus.

Nuclide

A type of atom specified by its atomic number, atomic mass, and energy state.

Radioactive decay

The process during which parts of a nucleus break off and are emitted as particles, changing the number of protons in the nucleus.

Alpha particle ($\alpha$)

A group composed of two protons and two neutrons emitted as a radioactive particle; equivalent to a helium nucleus ($^{4}_{2}\text{He}^{2+}$).

Beta particle ($\beta$)

A rapidly-moving electron emitted from a nucleus during radioactive decay when a neutron converts into a proton and an electron.

Gamma ray ($\gamma$)

High-energy electromagnetic radiation emitted by radioactive substances that travels at the speed of light.

Ionizing radiation

Emissions such as alpha particles, beta particles, and gamma rays that can ionize atoms with which they make contact.

Positron

A form of antimatter idential to an electron in every way except it has a positive charge ($+1$) rather than a negative charge.

Antimatter

Matter composed of antiparticles, such as positrons and anti-protons, that annihilate upon contact with regular matter, releasing energy.

Decay series

The predictable pattern of transmutations a radioactive atom undergoes on its way to reaching a stable element.

Half-life

The amount of time it takes for half of the atoms in a sample to decay to the next step in its decay series.

Geiger counter

A device used to measure radioactivity by clicking whenever it detects a radioactive emission.

Radioisotopic dating

A method that uses the concentration and decay rate of a radioactive substance, such as Carbon-$14$, to establish the age of an object.

Fission

The splitting of a heavy nucleus to create two or more lighter nuclei, releasing a large amount of energy.

Chain reaction

A repeating nuclear reaction that starts with the splitting of a heavy nucleus and continues as long as sufficient nuclear material remains.

Critical mass

The quantity of radioactive material necessary to sustain a self-sustaining fission chain reaction.

Nuclear reactor

A device in which a controlled nuclear fission reaction is used to generate heat for produces power.

Fuel rods

Long metal rods containing enriched uranium-$235$ fuel in the form of uranium oxide pellets.

Control rods

Rods composed of neutron-absorbing material, such as cadmium or boron, used to regulate the rate of fission in a nuclear reactor.

Moderator

A substance like water that slows down neutrons in a reactor core to increase the likelihood of successful collisions for fission.

Fusion

A nuclear reaction where the nuclei of two light elements merge to form the nucleus of a heavier element, producing vast amounts of energy.

Plasma

A state of matter at extremely high temperatures composed of separate electrons and positive nuclei, necessary for fusion reactions.