Step-by-step explanation:
We have to find the atom which electron configuration could end in the notation d6.
In the periodic table we can identify different blocks.
The elements that are in the middle of the periodic table (from group 3 to 12) they represent the d-block. They are the elements which electron configuration is supposed to end with the d.
The group 3 ends with the notation d1, the group 12 ends with the notation d10, while the one that ends in the notation d6 is the group 8.
The elements of the group 10 are Fe, Ru, Os and Hs. So the answer to our problem is Osmium.
Answer: Osmium