Question

Cl, F, Br, I (arrange in increasing order of electron affinity)​

Answer 1

Answer:

I<Br<F<Cl.

Hope it helps.

Answer 2

$Since \: the \: atomic \: size \: increases \: down \: the \: group,  \: electron \: affinity  \: generally \: decreases \: (At \: < I \: < Br \: < F \: < Cl \: ). \: An \:  electron \:  will \: not \: be \: as \: attracted \: to \: the \: nucleus, \: resulting \: in \: a low \:  electron \: affinity. \: However, \: fluorine \: has \: a \: lower \:  electron \: affinity  \: than \: chlorine. \:$