The redox half reaction
Again we need table X with the redox couples, where we meet a column with reductors and a column with oxydators.
Every line, two conjugated particles are joined.
No matter what book about chemistry, always is there a redox table, almost always with some small differences,
for example, the position of reductors and oxydators, the strong and the weak ones.
So be carfull.
Many oxydators and reductors only act in the presence of certain auxiliary substances.
For example, sulfate only can oxydise in the presence of an acid (ion H+).
The same particle (same substance) can occur more than one time in the redox table, on different positions, varying in strenghth.
Att.: this phenomena only occurs when using different auxiliary substances.
In principle always the strongest will react, but of course under the condition that those needed extra substances are really present.
Any chemist knows a lot of substances from the redox table by heart, not only the formulas, but also the names.
Try hard. You will become more critical when the media come with any statement.