"These products are good."
Translation:Ces produits sont bons.
There is a grey area here.
The choice between "bien" and "bons" will depend on the nature of the products.
If they are food products, "bons" will be the right adjective and it will mean "tasty" or "edible" (expiry date not reached).
If they are more technical products, "bien" will probably be better. "Mon téléphone est bien" works and "mon téléphone est un bon produit" will mean the same thing. But you won't say "mon téléphone est bon", unless you add what it is good at, like "mon téléphone est bon pour les photos".
No, bien ≠ good in this sentence...
Bon is usually an adjective and bien is usually an adverb. They correspond "roughly" to the English good/well.
One could say: ces produits sont bien emballés / these products are well packaged, where bien is modifying emballés.
C'est bien/c'est bon = It's good.
- to express an opinion.
Le film ? C'était vraiment bien ! / The movie? It was really good!
to express a physical sensation (taste, touch, etc.)
La soupe ? C'est bon ! / The soup? It's good!
when something is ready or to give a green light to something
For example, after verifying everything is ready for a trip. C'est bon ! = It's ready, we can go.
Ces produit son bien - bien does not have a different plural form. It does not differ with genders of numbers - it is a static adverb that is sometimes used as an adjective (see Sitesurf's response near the top of this thread).
However, If you typed Ces produit son bon - bon is an adjective that obeys all the rules of agreement (eg bonne / *bonnes if fem sing. / feminine plural ... etc).
In this instance "Ces produits" is pluaral = "These products" so, if you use the adjective "bon", it must be masculine plural - bons.
Therefore Ces produits sont bons is correct.