问题 问答题

金属在生活中有广泛的应用,没有金属,生活是难以想象的.

(1)从金属元素的原子结构分析,你认为大多数金属易与其他物质发生反应的根本原因是______.

(2)根据你平常的所见所闻及所学的化学知识,写出保护金属资源的方法(写一种即可)______.

答案

(1)原子在化学反应中的表现是由原子的最外层电子决定的,最外层电子少于4个易失电子,最外层电子多于4个易得电子.金属原子的最外层电子数一般少于4个,容易失去电子,因此大多数金属易与其他物质发生反应.故答案为:金属原子的最外层电子数一般少于4个,容易失去电子

(2)保护金属资源的方法有很多,例如:防止金属锈蚀;回收利用废旧金属;合理有效地开采矿物;寻找金属的替代品等等.故答案为:防止金属锈蚀

完形填空

It is a good idea to  1 a small present when you go to a  2 party in England or the USA. Flowers are always nice or you may bring a bottle of wine  3 you know what the family  4  . You should arrive on time or  5 minutes late. Don't get there early. If you are going to be there  6 fifteen minutes late, you should call and tell the host and hostess. Try to relax at the dinner table. If you don't know  7 to use the fork(叉子), the knife, or the spoon, just watch  8 and follow them. You can also ask someone next to you. If you like the food, say so. Of course, you will thank the host and the hostess  9 the meal and for their kindness. It's good to send a card or a “thank you” note the   10 day.

小题1:A. bring               B. take                 C. carry

小题2:A. breakfast           B. lunch                C. birthday

小题3:A. when                B. if                   C. so

小题4:A. eat                 B. drinks               C. drink

小题5:A. five                B. ten                  C. five to ten

小题6:A. less than           B. more than            C. about

小题7:A. why                 B. how                  C. what

小题8:A. other               B. the others           C. others

小题9:A. for                 B. of                   C. at

小题10:A. later              B. tomorrow             C. next

单项选择题