一、常见“题眼”归纳1.元素的原子结构与位置(1)只由质子和电子构成的原子是H,原子半径最小的是H;(2)周期序数等于族序数2倍的短周期元素是Li,;(3)族序数与周期序数相同的短周期元素有H、Be、Al;族序数是周期序数2倍的短周期元素有C、S;族序数是周期序数3倍的元素是0;(4)最外层电子数是次外层电子数2倍的元素是C;最外层电子数是 First, the common “title ” Induction 1. Atomic structure and location of elements (1) atoms composed only of protons and electrons is H, the atomic radius of the smallest is H; (2) the number of cycles equal to 2 times the number of family The short-period element is Li, (3) The short-period elements with the same sequence number and period number are H, Be and Al; the short period elements whose sequence number is 2 times the period number have C and S; Of the element is 0; (4) the outermost electron number is 2 times the outer electron number of the element is C; the outermost electron number is