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/입니다.^^
당신은 어느 그룹입니까?