Page 53 - ICC Science Dictionary (spreads)
P. 53
Word Definition Topic(s) Word Definition Topic(s)
quadrat A square frame of known area B7a, B7b radioisotope An isotope of an atom of an P4
used for sampling the abundance element that releases ionising
and distribution of slow or non- radiation. Isotopes of an element
moving organisms. have more or fewer neutrons
qualitative Results that are not expressed as B2 than each other. Also called a
numbers or numerical data, eg radioactive isotope.
they can be expressed as present radiotherapy Using ionising radiation to treat B3
or absent, or as colours. cancer by targeting cancerous cells.
quantitative Results that can be expressed B2 random Occurring without a pattern. B7a, B7b
using numerical values. Unpredictable. In statistics
quarry An area of land that is used to C10 where each item has an equal
remove rocks for use in industries. probability of being selected.
quarrying The removal of rocks from the land. C10 random error These cause readings to be spread Thinking
about the true value, due to results scientifically
radial field When field lines spread out from a P2 varying in an unpredictable way
single point. Eg an electron on its from one measurement to the next.
own will have a radial field. Random errors are present when
radiates Spreads out from a source. Energy P4 any measurement is made, and
is transferred as a wave. cannot be corrected. The effect of
random errors can be reduced by
radiation Anything that is emitted out from TP6, P6 making more measurements and
a central point, for example calculating a new mean.
electromagnetic radiation,
nuclear radiation, thermal range Range is the difference between Thinking
radiation or ionising radiation. the highest and lowest values in a scientifically
set of data.
radioactive When unstable atoms give off B2, P1, P4
particles that can be harmful to rarefaction An area of reduced pressure. In P6
humans. longitudinal waves, the particles
in areas of rarefaction are further
radioactive The process in which unstable atomic P4 apart than on average.
decay nuclei break apart or change,
releasing radiation as they do so. rate Per unit time or ‘per second’. For C10, P1
example, if 2,000 J are transferred
radioactive A radioisotope used to trace, eg the P4 over a period of 10 s, then the rate
tracer flow of blood through an organ. of transfer is 200 J/s or 200 W. This
value is the power rating.
