The most common oxidation numbers of fermium, Fm, are +2 and +3, though there are no stable isotopes (half-life times shorter than 100 days)
It shows some oxidation numbers. Generally it shows +4 oxidation numbers.
The fermium oxide is not known; the possible formula is Fm2O3.
0 in the elemental form, +2 and +4 in its compounds
Argon is very unreactive as it is a noble gas. Its common oxidation number is zero.
See the list of fermium isotopes at the link below.
It is a gas. Generally it shows -2 oxidation number.
-1 in bromide (most common). It can exhibit oxidation numbers from -1 to +7 (in HBrO4)
Argon doesn't form compounds and so its oxidation number is zero
-1 is most common in chlorides. However chlorine can exhibit oxidation numbers up to +7 in its compounds.
Bromine has an oxidation number of negative one, except when with oxygen or flourine.
It depends on the compound. Lead can have an oxidation state of either 2+ or 4+
Formulas for compounds