Cấu hình electron của Ni (Z = 28) là

A. Ar 3 d 8 4 s 2        

B.  Ar 3 d 7 4 s 8  

C.  Ar 3 d 5 4 s 5      

D.  Ar 3 d 9 4 s 1  

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

After the social science lecture all students are invited to take part in a discussion of the issues which were risen in the talk.

A.social science lecture

B.to take part

C.of the issues

D.risen in