답변 : 1-H 2-HE 3-Li 4-Be 5-B 6-C 7-N 8-O 9-F 10-Ne 11-Na 12-Mg 13-Al 14-Si 15-P 16-S 17-Cl 18-Ar 19-K 20-Ca
당신은 어느 그룹입니까?