【单选题】C H 4 分子中 C原子采用的杂化方式是:
【单选题】From this passage we can infer that ______.
A.
the school work was too difficult for Einstein
B.
Einstein did not receive college education
C.
A stupid boy can become a genius
D.
Einstein was careless with his school work
【单选题】_____ impressed me was the boy’s ability to deal with this kind of difficult physics problem.
【单选题】在下列分子中,碳原子采用 sp 2 杂化方式的是:
【单选题】关于原子轨道的说法正确的是( )
A.
凡是中心原子采取sp 3 杂化方式成键的分子其几何构型都是正四面体
B.
CH 4 分子中的sp 3 杂化轨道是由4个H原子的1s轨道和C原子的2p轨道混合起来而形成的
C.
sp 3 杂化轨道是由同一个原子中能量相近的s轨道和p轨道混合起来形成的一组能量相同的新轨道
D.
凡AB 3 型的共价化合物,其中心原子A均采用sp 3 杂化方式成键
【单选题】This exam was so difficult that only- student in our class passed it.
【判断题】红铜与青铜相比,硬度更小,不容易浇筑出大型器物。
【单选题】This mathematic problem was so difficult that no student and no teacher ______ able to solve it.
【单选题】_____ this report _____ in such a short time was quite a difficult exercise.
【判断题】红铜与青铜相比,硬度更小,不容易浇筑出大型器物。