Tungsten (W) is located in period 6 of the periodic table, meaning it has 6 electron shells. To find an element with the same number of electron shells, we need to look for elements that are also in period 6.
From the provided options:
- Gold (Au) is in period 6.
- Molybdenum (Mo) is in period 5.
- Nickel (Ni) is in period 4.
- Yttrium (Y) is in period 5.
The correct response is gold (Au), as it is in the same period (6) as tungsten (W) and thus has the same number of electron shells.