1. (2023高二下·上犹期末) 下表是部分短周期元素的原子半径及主要化合价，请判断以下叙述正确的是（  ）                                                                                                                                                                                

元素代号	a	b	c	d	e
原子半径/nm	0.130	0.118	0.090	0.037	0.073
主要化合价	+2	+3	+2	+1	-2