Page 32 - ICC Science Dictionary (spreads)

Word Definition Topic(s) Word Definition Topic(s)

group A vertical column in the periodic TC1, C1, C2 halide A halide ion is an ion formed when C4, C8
table containing elements with a halogen atom (an atom from
similar chemical properties. group 7) gains one electron. Halide
group 1 The first vertical column of C1 ions have a single negative charge.
elements in the periodic table, Ionic compounds containing
starting with lithium and ending halide ions may be called halides.
with francium. Also called the halogen An element placed in group C4
alkali metals. 7 of the periodic table, which

gut The digestive system. It is involved B2 starts with fluorine and ends with
in breaking down complex food astatine. The name 'halogen'
molecules and the absorption of means 'salt-producing' because
simple food molecules into the halogens produce a range of salts
bloodstream. when they react with metals.
gut bacteria Microorganisms that naturally TB4 haploid A sex cell (gamete) that contains B6
live in the intestine and help food one set of chromosomes.
break down. hard Able to resist wear, scratching and C10
Haber The industrial chemical process C1, C6, C10 indentation.
process that makes ammonia by reacting hazard Any chemical that can cause TC1, P4
nitrogen and hydrogen together. harm or damage to humans,

habitat A place where plants, animals B7a, B7b, C9, property, or the environment.
and microorganisms live. C10 heart Muscular organ that pumps blood B2
haemoglobin The red protein found in red blood B2, C9 around the body.
cells that transports oxygen round heart attack A condition where the supply of B2
the body. blood to the heart is suddenly

half equation An equation, involving ions and C4 blocked, usually by the build up
electrons, that describes the of fatty material in one or more
process happening at an electrode. of the coronary arteries. Heart
muscle is damaged in the process.
half-life The time it takes for the number of P4
nuclei of a radioactive isotope in a heart disease A wide range of conditions that B2
sample to halve. Also defined as the affect the heart.
time it takes for the count rate from heart failure A condition where the heart is failing B2
a sample containing a radioactive to pump sufficient blood around the
isotope to fall to half its starting level. body at the appropriate pressure.