Materials Vocabulary (KCC Yr 9 Science 2025)

Element

A pure substance made of only one kind of atom. Elements are the building blocks of other substances and can be found on the periodic table.

Metals

Elements that are good conductors of electric current and heat. On the left of the periodic table.

Non-metals

elements that are usually dull in appearance

Metalloids

Elements that have properties of both metals and nonmetals. Between the metals and non-metals on the periodic table.

Examples of substances that are elements

Gold

Examples of metals

Iron

Examples of non-metals

Oxygen

Examples of metalloids

boron

Monatomic elements

Elements that exist in nature as single atoms. Examples include helium and argon.

Diatomic elements

Elements that exist in nature as two atoms of the same bonded together. Types of molecules

Lattice Elements

Elements that arrange themselves in large

Compounds

Substances that contain atoms of two or more different elements chemically bonded in a fixed ratio.

Mixtures

Two or more pure substances (either elements or compounds) combined but not chemically bonded together. Alloys are mixtures of a metal and other metals or non-metals.

Pure substances

Substances that are either elements and compounds.

Impure substances

Substanes that are homeogenous and heterogenous mixtures.

Solids

A state of matter in which the object has a fixed shape and volume.

Liquids

A state of matter in which the object has a fixed volume but a variable shape.

Gas

A state of matter ion which the object has a variable shape and variable volume.

Diffusion

The process of gases expanding to fill their container.

Melting

State change from solid to liquid

Evaporation

State change from liquid to gas.

Condensation

State change from gas to liquid.

Freezing/solidification

State change from liqiud to solid.

Sublimation

State change from solid to gas.

Deposition

State change from gas to solid.

Proton

positively charge subatomic particle found in the nucleus.

Neutron

neutral subatomic particle found in the nucleus.

Electron

negatively charged subatomic partcile found orbiting the nucleus

Atomic number

the number of protons in an atom. Found on the periodic table.

Mass number

the sum of the number of neutrons and protons in an atomic nucleus.

Isotope

A form of an element that has the same number of protons but a different number of neutrons

Ion

A form of an atom that has a positive or negative charge due to electrons and protons not being equal

Valence shell

The outermist electron shell in an element

Electron configuration

the arrangement of electrons in an atom

Electron shell diagram

Diagram showing electrons in their shells around the nucleus of an atom.

Ground state of an atom

The lowest possible energy state of the electrons in an atom.

Annealing

Heating a metal to a specified temperature where recrystallisation occurs and allowing it to cool down slowly to room temperature

Quenching

Heating a metal to a specified temperature where recrystallisation occurred and quickly cooling it down in water or oil bath

Tempering

Heating a quenched metal to below recrystallisation temperature and allowing it to cool down in the air

Metals

Dense

Ductile

A term used to describe a material that can be pulled out into a long wire.

Malleable

capable of being beaten into shape

Lustrous

Shiny

Metal Alloys

Mixture of at leasrt one metal and one other substance to improve its properties.

Covalent bond

A bond between non-metal elements that involves the sharing of electrons to gain a full outer shell.

Covalent molecular compounds

A compound composed of two or more nonmetal elements bonded in individual subunits (e.g. water

Covalent network compounds

Non-metal elements or metalloids covalently bonded in a huge 3-D network (e.g. diamond

Allotrope

Different physics forms of the same element (e.g. graphite

Properties of covalent compounds

These vary but

Properties of ionic compounds

Brittle

Examples of ionic compounds

Sodium chloride (NaCl)

Examples of covalent compounds

Water (H2O)