These end in -tion too, but they are masculine.
J'assume l'entière responsabilité de cette action.
I take full responsibility for the action.
Je crois que son action était la bonne.
I believe that his action was in the right.
Il a investi beaucoup d'argent en actions.
He invested a lot of money in stocks.
FrenchTextbook teaches rules like this, in a full beginner course.
162 lessons, 4,000+ exercises, and 6+ hours of audio.