题目

下列分子或离子中，能提供孤电子对与某些金属离子形成配位键的是( )①H2O ②NH3 ③F－ ④CN－ ⑤COA. ①② B. ①②③ C. ①②④ D. ①②③④⑤ 答案：【答案】D【解析】如果这几种微粒中含有孤电子对就能提供孤对电子与某些金属离子形成配位键，根据其电子式判断即可．根据各微粒中各原子的成键情况，写出几种微粒的电子式，得出这几种微粒的路易斯结构式分别为：，据此可知，这几种微粒都能提供孤对电子与某些金属离子形成配位键，故选D 用方框内的词或词组的适当形式填空。 look after, every day, eat, sports, never, usually, hardly ever, how often, how many, often, habit, sometimes1. —What         do you play?       —I usually play soccer. 2. —                  do you eat vegetables?       —Every day. 3. I          eat junk food. I can't stand it. 4. I think I'm kind of unhealthy. I                    exercise. 5. I drink milk                      . It's a good          . 6. Please help me                    my pet dog when I am on holiday. 7. I like action movies very much, so I          go to the movies with my friends. 8.                     students are there in your school? 9. What do you            do on weekends?10. I like            fruit.