Radiation Concepts and Electricity Flashcards

Vocabulary practice flashcards generated from lecture notes covering physics foundations, atomic structure, electromagnetic radiation, electrostatics, and electrodynamics.

Matter

Anything that has mass and occupies space.

Radiation

Emitted energy that is transmitted through matter.

Energy

The force used to do work, measured in joules ($J$).

Law of Conservation of Matter and Energy

A theory advanced by Albert Einstein in 1905 stating that the sum of all matter and energy in the universe is constant; energy cannot be created or lost, but can be converted from one form to another ($E = mc^2$).

Mixture

A physical combination of two or more pure substances (elements or compounds) that are not chemically bonded, which can be separated by physical means.

Element

The simplest form of matter, made of only one type of atom, which cannot be broken down into a smaller form.

Compound

A substance made of different types of atoms chemically bonded together to form molecules.

Substance

A particular kind of matter with uniform properties.

Molecule

The smallest particle of a compound possessing the characteristics of that compound, consisting of two or more atoms chemically united.

Hydrogen Bond

A weak attraction between a slightly positive hydrogen atom from one molecule and a slightly negative, highly electronegative atom (such as oxygen, nitrogen, or fluorine) in another molecule.

Ionic Bond

A strong chemical attraction formed when electrically charged atoms (ions) stick together due to opposite charges after one atom transfers one or more electrons to another atom.

Covalent Bond

A chemical bond formed when two atoms share electrons to become more stable rather than transferring them.

Earnest Rutherford

New Zealand physicist/chemist who in 1911 described the atom as having a dense, positive nucleus surrounded by a cloud of negative electrons.

Neils Bohr

Danish physicist who in 1913 described the atom as a miniature solar system with negative electrons orbiting a central nucleus.

Erwin Schrödinger

Austrian/Irish physicist who established the foundation of modern physics with quantum physics or wave mechanics, describing particles as waves.

Quarks

Smaller particles of a strong force that make up protons and neutrons.

Proton

A basic atomic particle located in the nucleus with a positive charge, a mass number of $1$, and a mass of $1.673 \times 10^{-27}\,kg$.

Neutron

A basic atomic particle located in the nucleus with a neutral charge, a mass number of $1$, and a mass of $1.675 \times 10^{-27}\,kg$.

Electron

A fundamental subatomic particle orbiting the nucleus with a negative charge and negligible mass.

Atomic Number (Z#)

The number of protons contained within an atom's nucleus, which defines and distinguishes each element.

Isotopes

Atoms of the same element that have the same number of protons but a different number of neutrons.

Ionization

The process in which an atom gains or loses electrons, resulting in a net electrical charge without changing the atomic number ($Z\#$).

Atomic Mass Number (A#)

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

Electron Capacity Formula

Represented as $2n^2$, where $n$ is the orbital shell number, determining the maximum number of electrons an electron shell can hold.

Electron Binding Energy (Eb)

The energy needed to eject an electron from an atom, which depends on the electron's proximity to the nucleus and the number of protons in the nucleus.

Electron Volt (eV)

The energy gained by one electron when accelerated by one volt, used as a convenient unit for photon energy in radiology.

Valence Band

The outermost electron shell of an atom, which determines its chemical behavior and combining characteristics.

Cation

A positively charged ion formed when an atom gives up an electron ($+1$).

Anion

A negatively charged ion formed when an atom gains an electron ($-1$).

Octet Rule

The principle stating that an atom never has more than eight electrons in its outer shell, making an atom with eight valence electrons chemically stable or inert.

Work

The expenditure of energy when a force acts upon an object over a distance, defined mathematically as $\text{Work} = \text{force} \times \text{distance}$.

Potential Energy

Stored mechanical energy possessed by an object at rest because of its position, height, or configuration.

Kinetic Energy

Mechanical energy of motion.

Thermal Energy

Also known as heat energy, it is the energy resulting from the movement of molecules, measured by temperature.

Electrical Energy

Energy resulting from the movement of electrons within a conductor within the conduction band of an atom.

Nuclear Energy

Energy obtained by breaking bonds between nucleons within the nucleus of an atom.

Electromagnetic (EM) Energy

Radiant energy traveling through space at the speed of light in self-propagating waves composed of oscillating electric and magnetic fields.

Speed of Light (c)

The velocity of all electromagnetic radiation, equal to $3 \times 10^8\,m/sec$ or $196,000\,miles/sec$.

Photon

A discrete bundle or quantum of electromagnetic energy that travels as a wave but interacts with matter like a particle.

Planck's Constant (h)

A physical constant that relates photon energy to frequency ($E = h\nu$), equal to $4.15 \times 10^{-15}\,eV\text{-}sec$.

Wilhelm Conrad Röntgen

The scientist who discovered x-rays in 1895 and won the first Nobel Prize for physics in 1901.

Electrostatics

The study of stationary electric charges and the forces, fields, and potentials they create.

Ground Potential

The zero electric potential reference of the Earth, defined because the Earth is an infinite reservoir of both positive and negative charges.

Electrification

The process by which an object becomes charged by gaining or losing electrons.

Inverse Square Law of Electrostatics

States that the electrostatic force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.

Friction (Electrification)

A method of electrification where the abrasion of two conductive materials creates a transfer of charge between them.

Contact (Electrification)

A method of electrification where physically touching a charged body to a neutral body permits electrons to move and transfers charge.

Induction (Electrification)

The process where electric fields act on one another to induce a charge in a neutral object without physical contact.

Transformer

An electrical device that transfers electric energy between AC circuits by stepping up or stepping down voltage through electromagnetic induction.

Electrodynamics

The study of the movement of electric charges (electrons).

Ampere

The unit of electric current measuring the quantity of electrons flowing, equivalent to $1\,C/sec$ (where $1\,C = 6.24 \times 10^{18}\,\text{charges}$).

Potential Difference

The force or electromotive force (EMF), expressed in voltage, that drives electrons from areas of high concentration to low concentration.

Ohm's Law

The foundational electrical relationship expressed as $V = IR$, where $V$ is potential difference in volts, $I$ is current in amperes, and $R$ is resistance in ohms.

Power Formula

An equation calculating electric power expressed as $P = IV$, where $P$ is power in watts, $I$ is current in amperes, and $V$ is potential difference in volts.

Rheostat

A variable resistor that controls opposition to current flow in an electrical circuit.