1. Year 8 – The periodic table
KEY WORDS
Atom
The smallest particle of material that can exist on its own.
Nucleus
The centre of an atom
Electron
A tiny negative particle whizzing around the outside of the nucleus of an atom
Proton
A positive particle found in the nucleus of an atom
Neutron
A particle with no charge found in the nucleus of an atom
Element
A substance made from one type of atom.
Compound
A substance made from 2 or more elements that have reacted together.
Mixture
A mixture of two or more elements or compounds that have not reacted together.
Molecule
A particle made from a small group of atoms joined together.
Periodic Table
A list of all known elements listed together.
Reaction
When two or more substances react bringing about a chemical change.
Formula
Shows what elements make up a substance.
Equation
Shows how chemicals react with each other in a reaction.
Pure
A material made only from one substance. The substance could be an element or a compound.
Conservation of mass
The idea that the mass of reactants in a chemical reaction will be equal to the mass of product. In other words no atoms can be lost or gained during a reaction.
the horizontal rows are called periods
the vertical columns are called groups
An Atom