— _______ is your school like， Ann?— It is a large and beautiful campus with a 50-metre-long swimmin

题干

— _______ is your school like， Ann?

— It is a large and beautiful campus with a 50-metre-long swimming pool.

A：How

B：What

C：Where

D：Why

上一题下一题 0.0难度选择题更新时间:2013-09-23 05:57:21

B

①C、N、O的电负性由大到小的顺序为____．

②写出Cu的核外电子排布式____．

③化合物Cu（NH₃）₃（CO）Ac中，金属元素的化合价为____．

④在一定条件下NH₃和CO₂能合成尿素CO（NH₂）₂，尿素中C原子轨道的杂化类型为____；1mol尿素分子中，σ 键的数目为____．

⑤Cu₂O晶体的晶胞结构如图所示，若阿伏伽德罗常数为N_A，晶胞的边长为a pm，则晶体的密度为____ g•cm^﹣³．