Year 9 Chemistry ACH

Metal

A class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity.

Malleable

Able to be hammered or pressed out of shape without breaking or cracking.

Ductile

Able to be stretched into wires

Noble gases

Elements in Group 18 of the periodic table. Have no charge and are gases under normal conditions. (Helium, Neon, Argon, Krypton, Xenon, Radon)

Non-metals

An element that tends to be a poor conductor of heat and electric current; these generally have properties opposite to those of metals.

Valence electrons

Electrons on the outermost energy level of an atom

Atom

The basic building block of all materials; it consists of neutrons and protons surrounded by a cloud of electrons

Atomic model

The fundamental building block of all materials; it consists of a bunch of neutrons and protons surrounded by a cloud of electrons

Atomic number

The number of protons in a neucleus; the atomic number determines what type of atom it is

Atomic symbol

A short-hand notation for describing an atom; it consists of the chemical "letter(s)", atomic number and mass number

Compound

A pure substance that is made up of two or more different types of atom chemically bound together

Electron

A small, negatively charged particle; clouds of electrons surround the nucleus of an atom

Electron configuration

The number of electrons in each of the electron shells of an atom

Element

A substance made up of only one type of atom

Mass number

The number of protons and neutrons in an atom's neucleus

Molecule

A cluster of atoms that makes up an element or a compound

Neutron

A particle in the nucleus of an atom having the same mass as a proton but no overall charge

Nucleus

The centre of an atom, containing protons & neutrons

Periodic table

A table showing the symbols and often data of all 118 known types of atoms (elements)

Proton

A positively charged particle in the nucleus