Final answer:
A tungsten cation would be smaller than a neutral tungsten atom due to decreased electron-electron repulsions and an increased effective nuclear charge after electron loss. An anion, though less common for tungsten, would be larger.
Step-by-step explanation:
If tungsten (W) were to form an ion, the size of the ion would depend on whether it gained or lost electrons. Typically, when an atom forms an ion by losing electrons and becomes a cation, it becomes smaller than the neutral atom.
This size reduction occurs because there are fewer electron-electron repulsions and the effective nuclear charge on the remaining electrons increases, leading to a contraction of the electron cloud.
On the other hand, if tungsten were to gain electrons to form an anion (which is less common for metals), the ion would be larger due to increased electron-electron repulsions with the same nuclear charge.
Since tungsten is a heavy metal with a high atomic number, it would require significant energy to remove its inner-shell electrons as indicated by its use in applications such as anodes in x-ray tubes, where high voltages are needed to knock out those inner electrons. Therefore, a tungsten cation would be smaller than the neutral tungsten atom.