GLOSSARY - Archaeological Chemistry - page 491

intensity See light intensity, radiation intensity .
interference (of waves) The constructive or destructive interaction between waves
traveling through a medium.
ion An atom or group of atoms that, because of the gain, or loss, of electrons , has a
negative (see anion ) or positive (see cation ) electric charge.
ion, hydroxyl See hydroxyl ion .
ionic bond See bond, ionic .
ionization A process in which ions are created from atoms or molecules by the addi-
tion (when anions are formed) or subtraction (when cations are formed) of electrons .
ionizing radiation See radiation, electromagnetic .
iridescence The property of very thin transparent colorless films, to scatter visible
light and exhibit a variety of rainbowlike changing colors, as displayed by mother
of pearl and weathered glass .
iron, bloomery An early form of iron also known as bloom , produced mostly in a
solid state as iron sponge, without melting either the ore or the metal .
iron, cast An alloy of iron and carbon containing more than 0.9% (generally between
2-4%) carbon, which is very brittle and not malleable , either when hot or when
cold; see casting .
iron, pig The brittle product of smelting iron , suitable for casting .
iron, wrought A ferrous alloy suitable for forging ; it is composed of iron , carbon (less
than 3%) and small amounts of slag .
iron sponge See bloomery iron .
iron vitriol See green vitriol .
irradiation The exposure of something, matter , for example, to radiation .
isomers Molecules that have the same chemical formula but different structure,
because the atoms in their molecules are arranged differently.
isomer, optical One of two substances whose molecules have the same chemical
formula but different structures, each molecule containing one or more asymmet-
ric ( chiral ) carbon atoms and, therefore, not superimposable on each other; also
known as stereoisomer ; see enantiomer.
isotope One of the different forms of atoms of the same element , which have the
same number of protons and therefore share the same atomic number , but differ in
the number of neutrons in their nuclei .
isotope, daughter The generic name for isotope s formed as a result of the radioac-
tive decay of other isotopes known as the parent isotopes .
isotope, parent A radioactive isotope that decays into a different isotope known by
the generic name daughter isotope .
isotope, primordial An isotope created at the time of the creation of the earth.

isotope, radioactive An isotope that undergoes radioactive decay .

isotope, radiogenic See radiogenic isotope.

isotope, stable An isotope that does not undergo radioactive decay .