I'd like to start off by introducing myself. I've always been interested in all types of sciences but lately, I've taken an interest in chemistry. I graduate from high school in June and am looking into environmental science/conservation as a career. So since I required a couple of credits in chemistry, I signed up for some chemistry classes and have become interested in chemistry during the course of those classes (particularly with alkali and alkaline earth metals, metalloids, and halogens).
Anyhow, my first question is this. If superacids are defined as being stronger than concentrated sulfuric acid, why are hydrobromic acid and hydriodic acid not considered superacids? I've heard that HCl is marginally stronger than H2SO4, so why are HBr and HI, which are stronger than HCl, not considered to be superacids?
Also, why is it that hydrogen halides (except HF) are stronger than sulfuric acid, which is diprotic?