[pimcub2011]

if an element's electron configuration is:

[noble gas]ns^2 (n-2)f^6

I know it's either a lanthanide or an actinide but what group would you say that it's in?

[pimcub2011]

I've tried group 3, 7, 8, and 9 but none of them are correct

[ARGOS++]

Dear pimcub2011;

If I interpret the formula correct and rewrite it:
   [Noble gas] ns²  (n-2)f⁶  so the lowest n can only be 6 or 7, because lowest possible f is what?.
But for n = 7 there is no element with 5f⁶.

So do the check for n = 6 on the table and be surprised!

I hope to have been of help to you
Good Luck!
                    ARGOS⁺⁺