... l A 18 , 21, 20 B 18 ,20, 21 C 12 ,14 ,14 D 12 ,14 ,20 Cõu 9: Nguyờn t X cú tng s ht p,n,e l 52 v s l 35 Cu hỡnh electron ca X l A 1s2 2s2 2p6 3s2 3p6 B 1s2 2s2 2p6 3s2 3p5 C 1s2 2s2 2p6 3s2 3p4 D 1s2 ... P,C,N,S,F,Cl D C,N,P,S,Cl,F Cõu 18 / Tỡm cu hỡnh electron vit sai a Na+ (Z =11 ) 1s22s22p63s2 b Na (Z =11 ) 1s22s22p63s1 c F ( = 9) 1s22s22p5 d F-(Z=9) 2 1s 2s 2p6 Cõu 19 / Ion X 2- cú cu hỡnh electron lp ... 3p64s2 3d105s2 4p3 45 Cõu 10 Mt nguyờn t cú kớ hiu l 21 X , cu hỡnh electron ca nguyờn t X l a 1s22s22p63s23p64s23d1 b 1s22s22p63s23p63d14s2 c 1s22s22p63s23p63d3 d 1s22s22p63s23p64s23d1 Câu 11: Tổng...