public class Reaction
{
    public Reaction (Chemical name, Chemical[] reactants)
    {
        _name = name;
    }

    private Chemical _name;
}
@@ -73,16 +73,34 @@
 eactants
+, int%5B%5D quantities
 )%0A    %7B%0A
@@ -129,36 +129,168 @@
     
-%7D%0A%0A    private Chemical _name
+    _reactants = reactants;%0A        _quantities = quantities;%0A    %7D%0A%0A    private Chemical _name;%0A    private Chemical%5B%5D _reactants;%0A    private int%5B%5D _quantities
 ;%0A%7D

Update Reaction.java