Answer:
1. (S,O) < (Se,S) < (C,H) = (H,I) = (H,F) < (Si,Cl) < (K,Br)
Explanation:
The covalent character always increases down the group, this is because ionic character decreases down the group and also electronegativity.
In the same way, Covalent character always decreases across a period because electronegativity increases across a period.
The higher the electronegativity values between the two atoms, the more ionic it will be.