Acidity increases going DOWN periodic table due to stabilization from size, but going UP/RIGHT due to electronegativity and holding on to electrons, amongst other trends.
I am wondering why HCl and the rest of the acids down the group are considered to be strong acids, but HF is considered to be a very weak acid? Why is the F- ion such a strong base and i guess you could say an exception to the trends observed.
Also, are the halogens/halides just a funny group? Looking at nucleophilicity with them as well right now and that specific group seems to pose an exception to the stated trend that nucleophilicity increase going up this group rather than down as observed in the other groups?