Radiography Physics and Radiation Protection: Atomic Structure and Radiation Concepts

Vocabulary flashcards covering atomic physics, atomic structure, chemical bonding, periodic table nomenclature, atom relationships, and radiation protection basics based on lecture notes.

Atom

The basic building block of all matter in the universe, consisting of a small, dense, positively charged nucleus surrounded by negative electrons.

Bohr Atom

An atomic model proposed by Niels Bohr in 1913 expanding on Rutherford's model, stating that electrons occupy set orbits around the nucleus and emit light or radiation only when jumping between orbits.

Ion

An atom that carries a net positive or negative charge because the number of electrons does not equal the number of protons.

Element

A pure substance that cannot be decomposed into a simpler substance and can only be broken down to a single atom with identical properties.

Molecule

A chemical structure formed when two or more atoms join together chemically.

Compound

A molecule that contains at least two different elements or molecules.

Covalent Bonding

A weak chemical bond resulting from the sharing of one or more pairs of electrons by two atoms with unpaired outer-shell electrons.

Valence Electron

An electron located in the outer shell of an atom.

Ionic Bonding

A strong chemical bond in which one or more electrons are transferred from one atom to another, forming positive and negative ions that attract each other through electrostatic forces.

Electron

The smallest subatomic particle, carrying a negative charge, located in shells around the nucleus, with an atomic mass of $0.000549$.

Proton

A positively charged subatomic particle located in the nucleus with an atomic mass of $1.00728$, which determines the chemical characteristics of the atom.

Neutron

A neutral subatomic particle located in the nucleus with no charge and an atomic mass of $1.00867$.

Atomic Number ($Z$)

The number of protons in an atom, which equals the number of electrons in a stable atom.

Atomic Mass Number ($A$)

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

Dimitri Mendeleïev

The Russian chemist who constructed the periodic table in 1869 to classify chemical elements according to their chemical properties.

Periodic Table Shells

The 1 to 7 horizontal rows on the periodic table representing the maximum number of electron shells around an atom.

Periodic Table Groups

The 1 to 18 vertical columns on the periodic table containing elements with similar chemical properties and the same outer-shell electron characteristics.

Isotope

Atoms that have the same atomic number ($Z$) or proton number, but different atomic mass numbers.

Isobar

Atoms that have the same atomic mass number ($A$), but different atomic numbers.

Isotone

Atoms that have the same neutron number ($A - Z$), but different atomic numbers and mass numbers.

Isomer

Atoms that have the same atomic number and atomic mass number, but differ in their nuclear energy arrangement.

Ionizing Radiation

Radiation that produces an ion pair (a charged particle) by causing an atom to gain or lose an electron.

Manmade Ionizing Radiation

Ionizing radiation generated by an x-ray tube, which can be controlled by selecting exposure factors.

Radiation Protection

The requirement to safeguard individuals against significant and continuing radiation exposure to avoid adverse biological consequences.

Benefit versus Risk Principle

The fundamental principle requiring that the potential benefits of exposing a patient to ionizing radiation must outweigh the potential risk of adverse biological effects.