Elementary substances 
H2
Hydrogen (video) 
Reduction of iron(III) oxide by the hydrogen
Reduction of copper(II) oxide by the hydrogen
Reductions of hydrogen by metal oxides
Production of hydrogen by electrolysis of water
Fe
Formation of rust from iron
P4
The discovery of phosphorus (alchemy)
O2
Carbon combustion reaction in O2 
White phosphorus combustion reaction in O2
Sulfur combustion reaction in O2
Sodium combustion reaction in O2
Magnesium combustion reaction in O2
Combustion reactions of non-metals in O2(video)
Metal combustion reaction in O2(video)
Oxidations of metals and non-metals by oxygen
Establish combustion equations;
Production of oxygen by electrolysis of water
C
The carbon allotropes: diamond and graphite
Other elementary substances
Some common non-metals
Some common metals
The compounds: Names and formulas valences
The compounds: Names and formulas valences (exercises)
HCl
Preparation and properties of hydrochloric gas
Preparation and properties of hydrochloric acid
H2O
Water
Organic substances
Organic substances
Other compounds
The blast furnace: reduction of iron oxide
Rust: iron oxidation
The reactions of acids (exercises)
The reactions of acids
Description of some common acids: hydrochloric, sulfuric, nitric acid
The thermal agitation in a non-metal (animation)
Evaporation (animation)
Diffusion (animation)
Substances: Physical properties
Substances: Arrangement of atoms
Conventional colors of atoms
The periodic table
The simplified periodic table