Chemical Equations cont.

Now for some challenging exercises
Two hydrogen molecules colliding with one oxygen molecule. An oxygen molecule rushing in Two water molecules formed . Explanation of formulae and how to write them. Chlorine atom has the symbol "Cl" Hydrogen atom has the chemical symbol "H" A molecule of chlorine collides with a molecule of hydrogen Two molecules of hydrogen chloride (HCl) are formed. Aluminium  atom has the symbol "Al" Oxygen atom has the symbol "O" Four aluminium atoms collide with  three oxygen molecules. Two units of aluminium oxide are formed Carbon atom has the symbol "C" Oxygen atom has the symbol "O" Hydrogen atom has the symbol "H" Two methane molecules collide with seven oxygen molecules Six water molecules and four carbon dioxide molecules are formed.