AVSEPR

Q. Which of the following has a $S-S$ linkage ?

1. $S{O}_4^{2-}$
2. $S_2{O}_8^{2-}$
3. $S_2{O}_5^{2-}$
4. $S_2{O}_7^{2-}$

Q. In which of the following molecules are all the bonds not equal?

1. $Al{F}_3$
2. $N{F}_3$
3. $Cl{F}_3$
4. $B{F}_3$