The element that does not belong to the same period of the remaining elements (modern periodic table) is:

Let us identify the periods of each element:

- Iridium (Ir): Atomic number 77, Period 6 (6th row, 5d transition metal)

- Platinum (Pt): Atomic number 78, Period 6 (6th row, 5d transition metal)

- Osmium (Os): Atomic number 76, Period 6 (6th row, 5d transition metal)

- Palladium (Pd): Atomic number 46, Period 5 (5th row, 4d transition metal)

Iridium, Platinum, and Osmium all belong to Period 6, while Palladium belongs to Period 5.

The correct answer is Option 4: Palladium.