單項選擇題
A.8 B.18 C.8~18 D.8~32
A.3d34s1 B.3d34s0 C.3s23p63d5 D.3s23p63d34s2
A.3d24s1 B.3d34s0 C.3s23p63d64s1 D.3s23p63d3