Answer:
Good Question
see Negative ions are those which gain electrons to attain stability
Now, We know All metals tend to donate electrons which inturn results in positive charge
Now Have a closer look at options
a) F
It is fluorine
it's configuration is 2,7
that means it requires one electron to complete it's octet from 7 to 8
therefore, it will gain one electron which results in
b)Li
lithium is metal having one electron in outermost shell So it will rather loose electron to attain stability
c)Ne
Neon is Noble gas which exists in neutral stare
d)S
Sulphur needs 2 more electrons to attain stability
therefore it exists as negative ion
e)Al
Aluminum is metal So it exists as positive ion
f)Be also exists as positive ion