The element palladium has ten valence electrons in its 4d shell, its outermost shell. Numerous elements adhere to the octet rule, according to which they are deemed to have a full outer shell if they have eight electrons. Transition metals and heavier elements are exceptions; they are more stable when their outer shells have more electrons.
The asteroid Pallas was named after the Greek goddess of wisdom. The element was discovered by William Hyde Wollaston in 1803. It is most frequently discovered in deposits of platinum, nickel, and gold. With an atomic weight of 106 and an atomic number of 46, it is a solid element at ambient temperature.