Final answer:
None of the options provided, Molybdenum (Mo), Ruthenium (Ru), Palladium (Pd), or Silver (Ag), has a half-filled 6p subshell as they all have their outermost electrons in d-subshells. An element with a half-filled 6p subshell would be bismuth (Bi), which is not listed.
Step-by-step explanation:
To determine which atom is expected to have a half-filled 6p subshell, we must look at the electron configurations of the elements listed to identify the one with three electrons in the 6p subshell. When analyzing the given options a) Mo (Molybdenum), b) Ru (Ruthenium), c) Pd (Palladium), and d) Ag (Silver), we find that none fit the criteria for a half-filled 6p subshell, as they belong to the d-block of the periodic table. A half-filled 6p subshell is characteristic of elements in the p-block with atomic numbers starting from 81, which corresponds to thallium (Tl), and moving three places to bismuth (Bi) with the atomic number 83, thus it is not listed among the options provided. The given elements all have their outermost electrons in d-subshells rather than p-subshells.