got a question in Chemistry ch.5 please help!!

[Nada911]

why doesn't iron 3 carbonate oxidize easily when exposed to atmospheric air???
Need the answer ASAP ....thanks

[مستر احمد عبد الوهاب]

all iron 3 salts can`t oxidized as the most stable state of the iron is Fe+3 as the d-sublevel is half filled with electron