Plz expalin this also 3. factor #2: as electronegativity is a rough measure how effect

More eletronegative atom can hold-ve more easily

and it decreases down the group.....electronegative atom hold negative charges effectively

see electronegativity is the tendency of element to attract the shared pair of electron towards itself..so electronegative atom acquires negative charges effectively

electronegativity increases along the period from left to right...so F is most electronegative than O than N

Eletronegativity is a relative concept. Let Suppose you have H-F molecule which a covalent molecule i.e bond is formed by sharing pf eletron. But flourine has more hold on the elec...

and one more thing the positive charges on electronegative atom makes it unstable

hope this much helps shweta🙏