Question

The correct electronic configuration of the element Au is

• A. \([Xe]4f^{14}5d^{10}6s^2\)
• B. \([Xe]4f^{14}5d^9 6s^2\)
• C. \([Xe]4f^{14}5d^{10}6s^1\)
• D. \([Xe]4f^{14}5d^9 6s^1\)

Hint:

Elements like Cu, Ag, and Au show exceptional electronic configurations because completely filled \(d^{10}\) subshells provide extra stability.

Answer 1

The Correct Option is C

Step 1: Recall periodic trends for atomic radius.
Across a period: radius decreases (N>O, P>S). Down a group: radius increases (P,S>N,O).

Step 2: Combine trends to order.
O<N (same period, O right of N). N<S (S in 3rd period, N in 2nd). S<P (same period, S right of P). So O<N<S<P.

Step 3: Final Answer:
O<N<S<P (option 3).