Physical Science - Nuclear Reaction & Nucleosynthesis

Vocabulary flashcards covering key terms and concepts in nuclear reactions, subatomic structure, nucleosynthesis, nuclear notation, isotopes, and transmutation.

Atoms

Structures composed of a central nucleus surrounded by orbiting electrons.

Nucleus

The central core of an atom that consists of positively charged protons and neutral neutrons.

Element

A substance whose specific identity is determined by its number of protons.

Atomic Mass

The combined number of protons and neutrons in an atom.

Nucleosynthesis

The cosmic origin and formation of atomic nuclei, which mainly occurs when lighter elements combine or heavier elements break apart.

The Big Bang

The event that created the initial primordial, lightest elements—primarily H, He, and traces of Li.

Stellar Formation

The process in which gravity pulls H and He together to form stars, where extreme temperature and pressure drive nuclear fusion to forge elements from Be to Fe.

Iron ($\text{Fe}$)

The thermodynamic limit for normal stellar fusion.

Stellar Explosion

Catastrophic cosmic events such as supernovae and neutron star collisions that provide massive energy inputs to create elements heavier than Fe, such as Gold, Platinum, and Uranium.

Nuclear Fusion

A reaction through which light nuclei combine to form a heavier nucleus, generating less nuclear waste.

Nuclear Fission

The splitting of a heavy nucleus into lighter nuclei, which sustains power plants and nuclear weapons and produces less radioactive products.

Mass Number ($A$)

The sum of the number of protons plus neutrons in a nuclide, calculated as $A = Z + N$.

Atomic Number ($Z$)

The number of protons or total positive charge in a nuclide.

Neutron Number ($N$)

The number of neutrons in the nucleus, calculated as $N = A - Z$.

Nuclear Notation

A representation showing an element symbol $X$, mass number $A$, and atomic number $Z$ in the form ${}_Z^A X$.

Isotopes

Atoms of the same element with the same atomic number ($Z$) and proton count, but a different mass number ($A$) and neutron count.

Protium

A type of Hydrogen isotope containing 1 proton and 0 neutrons.

Deuterium

A type of Hydrogen isotope containing 1 proton and 1 neutron.

Tritium

A type of Hydrogen isotope containing 1 proton and 2 neutrons.

Transmutation

The process of changing one element to a different element by a decaying process.

Nuclear Decay Reaction

Also called radioactive decay; a process where an unstable nucleus emits radiation and transforms into daughter nuclei that have lower mass and/or lower energy (more stable) than the parent nucleus.

Nuclear Transmutation Reaction

A reaction where a nucleus reacts with a subatomic particle or another nucleus to form a product nucleus that is more massive than the starting material.

Radioactivity

A natural and spontaneous process by which unstable atoms of an element emit or radiate excess energy in the form of particles or waves.

Ionising Radiation

Particles or waves emitted during radioactivity that have the ability to remove electrons from the atoms of any matter they interact with.