Normalization of similar attributes (same information)

Hello,

if I have a table like this:
school:= SID (PK), ..., room1, room2, room3, ..., roomX

which needs to be normalized, against which NF is this multi-column attribute room ?

I know it should look something like this if there's a 1:m relationship
school:= SID(PK), ...
room:=RID(PK), SID(FK)

but which NF is it breaking?

Edit:
Okay since there is just one primary key in this relation, it can't be the second NF. Neither third, because there is no other attribute, but the pk, which determines the attributes room1, room2, room3.
So this sort of repetition is also against the first normal form?