Download P4 definitions

P4 – Key Words
Activity
Alpha particles
Alternating current or
voltage
Ammeter
Ampere (A)
Amplitude
Atomic number
Background Radiation
Becquerels (Bq)
Beta particles
Boron control rods
Carbon-14
Chain reaction
Charge(s)
Circuit breakers
Cold fusion
Compressions
Conductors
Cosmic rays
Count rate
current
Defibrillator
Average number of nuclei that decay every second
Radioactive particles which are helium nuclei (helium atoms
with no electrons so they have a positive charge).
An electric current that is not a one way flow.
Meter used in an electric circuit for measuring current
The unit used to measure electric current, often
abbreviated to amp
The distance the wave moves from its rest position
The number of protons found in the nucleus of an atom
Ionising radiation from space and rocks, especially granite,
that is around us all the time but is at a very low level.
Unit of activity or count rate; 1 Bq = 1 count per second
Particles given off by some radioactive materials (they
have a negative charge)
Rods that are raised or lowered in a nuclear reactor to
control the rate of fission
A radioactive isotope of carbon
A reaction where the products cause the reaction to go
further or faster, e.g. nuclear fission
Can either be positive or negative. Opposite charges
attract. The same charges will repel each other.
Resettable fuses
Attempts to produce fusion at normal room temperature
that have not been validated since other scientists could
not reproduce their results.
Particles push together, increasing pressure
Electrical conductors allow electricity to flow through
them
Radiation from space that contributes to background
radiation
Average number of nuclei that decay every second
Flow of electrons in an electric circuit
Machine which gives the heart an electric shock to start it
Direct current
Double insulated
Earth wire
Earthed (electrically)
Electromagnetic waves
Electrostatic
attraction
Electrostatic dust
precipitators
Electrostatic paint
sprayer
Enriched uranium
Fission
Frequency
Fuel rods
Fuse(s)
Fusion
Fusion bombs
Gamma rays
Geiger counter
Geiger-Muller tube
beating regularly
An electric current that flows in one direction only.
An electric device in which there are at least two layers of
insulation between the user and the electric wires.
The third wire in a mains cable which connects the case of
an appliance to the ground so that the case cannot become
charged and cause an electric shock
Connected to the ground at 0V
A group of waves that carry different amounts of energy –
they range from low frequency radio waves to high
frequency gamma rays
Attraction between opposite charges
Charged plates inside factory chimneys remove dust
particles from smoke
Charges paint droplets to give even coverage
Uranium containing more of the U-235 isotope than occurs
naturally
Splitting apart, especially of large radioactive nuclei such
as uranium
The number of waves passing a set point per second.
Rods of enriched uranium produced to provide fuel for
nuclear power stations
A special component in an electric circuit containing a thin
wire which is designed to melt if too much current flows
through it, breaking the circuit
The joining together of small nuclei, such as hydrogen
isotopes, at very high temperatures with the release of
energy
Hydrogen bombs or H-bombs based on fusion reactions
Ionising electromagnetic waves that are radioactive and
dangerous to human health – but useful in killing cancer
cells.
A device used to detect some types of radiation
A device used to detect some types of radiation
Gel
In ultrasound scanning, placed on the skin so that nearly all
the ultrasound passes into the body and is not reflected
by the skin.
Generator
Device that converts rotational kinetic energy to electrical
energy
Granite
Mineral containing low levels of uranium
Graphite
A type of carbon used as a moderator in a nuclear power
station
Half-life
Average time taken for half the nuclei in a radioactive
sample to decay
Helium
Second element in periodic table; an alpha particle is a
helium nucleus
Hertz (Hz)
Units for measuring wave frequency
Ionises
Adds or removes electrons from an atom leaving it
charged
Ions
Charged particles (can be positive or negative)
Isotopes
Atoms with the same number of protons but different
numbers of neutrons
Lead
Heaviest element having a stable isotope; all isotopes of
the elements above it in the periodic table are unstable
Live wire
Carries a high voltage into and around the house
Longitudinal wave
Wave in which vibrations are in the same direction as the
direction in which the wave moves.
Mass number
The number of protons and neutrons in a nucleus
Moderator
Material used to slow down neutrons in a nuclear power
station
Neutral wire
Provides a return path for the current in a mains supply to
a local electricity substation
Neutrons
Small particle which does not have a charge found in the
nucleus of an atom.
Nuclear equation
Equation showing changes to the nuclei in a nuclear
reaction
Nuclear power stations Power stations using the energy produced by nuclear
fission to generate heat
Nucleons
Protons and neutrons (both found in the nucleus)
Pitch
Whether a sound is high or low on a musical scale
Potential difference
Radioactive waste
Radiocarbon dating
Radiographer
Radioisotope
Radiotherapy
Rarefractions
Ratemeter
Resistance
Rheostat
Shock
Smoke detector
Sparks
Stable (nucleus)
Superconductors
Tracers
Transmitted
Transverse wave
Ultrasound
Uranium
Another word for voltage (a measure of the energy
carried by the electric current)
Waste produced by radioactive materials used at nuclear
power stations, research centres and some hospitals
Method of dating some old artefacts using Carbon-14
A technician who works in a hospital radiography
department, possibly taking x-rays or treating some types
of cancer with radiation
Isotope of an element that is radioactive
Using ionising radiation to kill cancer cells in the body
Particles are further apart than usual, decreasing
pressure
A device that measures the amount of radiation detected
by a Geiger-Muller tube
Measurement of how hard it is for an electric current to
flow through a material
A variable resistor
Occurs when a person comes into contact with an
electrical energy source so that the electrical energy
flows through a portion of the body
Device to detect smoke, some forms of which contain a
source of alpha radiation
Type of electrostatic discharge briefly producing light
and sound
(nucleus) is not radioactive; it will not decay
Materials that conduct electricity with little or no
resistance
A radioactive, radiation-emitting substance used to follow
movement of a particular chemical, e.g. nuclear medicine,
tracking the path of an underground pipe, etc.
Radiation passing through an object
Wave in which the vibrations are at right angles to the
direction the wave is moving
High-pitches sounds which are too high for detection by
human ears
Radioactive element with a very long half-life used in
Van de Graff
generator
Variable resistor
Voltage
Voltmeter
Wavelength (λ)
x-rays
nuclear power stations
A machine which uses a moving belt to accumulate very
high charges on a hollow metal globe
A resistor whose resistance can change
A measure of the energy carried by an electric current
(also called the potential difference)
Instrument used to measure voltage or potential
difference in volts (V)
Distance between two wave peaks
Ionising electromagnetic waves used in x-ray photography
(used to generate pictures of bones)