# Trends of electron affinity

Trends for electron affinity going across the group increases negatively.

Does this mean Noble gases's electron negativity is more negative than halogens ?

I'm confuse here .

Noble gases should have a positive electron affinity as adding an electron would make it unstable and thus , will not form.

But for halogens , their attraction for that 1 electron to fill up the p subshell is very strong.

But according to the theory that electron affinity increase negatively across the period, does this theory has an exception of noble gases ?

Next , what about Be and Mg ? Their electron affinities are not negative .

Not exceptions, but see, theories says that going $L→R$ electron affinity increases upto Halogens.
For the noble gases, $\Delta_{eg}H$ is $(+)ve$ (Energy required.) While electron affiniy is $0$. Which implies no tendency to lose $e^-$s.
For $Be$ the small size and nuclear charge are responsible and which is related to $Mg$ due to diagonal relationship.