Page 203 - The Periodic Table Book

Crystal Electrolysis Expand Hardness
A naturally occurring solid A process in which a To make or become bigger. A measure of how Glossary
substance whose atoms are compound is split into simpler Solids, liquids, and gases easy it is to scratch or
arranged in a regular three substances using an electric usually expand when the cut a substance with
dimensions pattern. current. Many elements, such temperature rises. another substance.
as aluminium, are purified
Decay from their compounds in Fission Hydroxide
A process in which ores in this way. A process in which the A type of compound
unstable atoms of nucleus of an unstable atom containing hydrogen and
radioactive elements break Electrode splits in two when it collides oxygen, and normally
apart. The atoms of one An electrical contact in an with a neutron. It releases a metallic element.
element are transformed electric circuit. Electrodes more neutrons that start the
into those of another can have a positive or cycle again, and this continues This is a chunk
element during decay. negative charge. as a chain reaction. Many of ytterbium,
unstable nuclei undergo fission a lanthanide.
Density Electron spontaneously, without being
The amount of matter A negatively charged particle hit by a neutron. Fission
held within a known inside an atom. Electrons releases a lot of energy. The
volume of a material. orbit the atom’s nucleus (or process is used to generate
core) in layers called shells. electricity in nuclear power
Dissolve They are also exchanged plants, and it can trigger
To become completely or shared by atoms to atom bomb explosions.
mixed into another substance. make bonds that hold
In most cases, a solid, such molecules together. Flammable
as salt, dissolves in a liquid, A way of describing a material
such as water. Element that can catch fire easily.
A pure substance that cannot
Earthenware be broken down into any Fusion
A basic form of simpler substances. Elements A process in which small
pottery, in which clay are the building blocks of atoms, such as those of
is heated to make it matter. There are 118 known hydrogen, are fused together
form hard structures. elements on Earth. with such force that they
merge to form larger
atoms, while releasing
a lot of energy. The Sun
is powered by the fusion
This element of hydrogen atoms into Ion
calcium is in helium in its central core. An atom or a group of atoms
crystal form. that have an electric charge.
Gas While atoms have no overall
A state in which the particles charge, they become positive
of matter (atoms or molecules) ions if they lose electrons
are not attached to each other, or negative ions if they
and move freely. A gas can gain electrons.
flow, take any shape, and fill
any container. Insulator
A substance that does not let
Group heat or electricity flow easily
A set of elements in a through it.
column in the periodic table.
Elements in a group have Isotope
similar properties because A form of an element with
each atom has the same atoms that have the same
number of electrons in its number of protons but a
outer shell. different number of neutrons.

Halogen Lanthanide
A member of a group near A member of a set of metals
the far right of the periodic with relatively large atoms. The
table. Halogens form salts elements in this series sit with
with metals. They are reactive, the actinides, below the main
non-metallic elements. part of the periodic table. 201

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