题干

根据下列短周期元素性质的数据判断,下列说法正确的是(   )

⑤[

原子半径/1010m

0.66

1.36

1.23

1.10

0.99

1.54

0.70

1.18

最高正化合价

+2

+1

+5

+7

+1

+5

+3

负化合价

﹣2

﹣3

﹣1

﹣3

A:元素①⑧形成的化合物具有两性

B:元素⑦位于第二周期Ⅴ族

C:元素④⑤形成的化合物是离子化合物

D:元素⑥的最高价氧化物对应水化物碱性最强

上一题 下一题 0.0难度 选择题 更新时间:2015-01-29 06:29:51

答案(点此获取答案解析)

A,D

同类题1

阅读理解

B

    One morning a boy went home with his father. They noticed a pair of old shoes by the roadside. They thought the shoes might be a poor man's. In fact, the owner of the shoes was working in the field nearby, and he had nearly finished his work.

    The boy said to his father, "Let's play a trick on the man—we hide his shoes, and wait to see what he will do when he can't find them."

    "My boy, we should never have fun by tricking other people like that," answered his father. "Instead, let's put a coin in each of the shoes, and watch he will do."

    The boy did so, and then they hid nearby.

    The man soon back to get h is shoes, but when he put his foot into one of his shoes, he felt something in it. He bent(弯曲)down and found the coin.

    Surprise appeared on his face. He looked at the coin for a minute, and then looked around, but nobody could be seen. He then went on to put on the other shoe, but he was even more surprised to find the second coin.

    He then went down on his knees, looked up to the sky and said thanks aloud. He said his wife was ill and his children were hungry. He wanted to buy some bread for them.

    The boy was deeply moved.

    "Now," said his father, "you must be much more pleased than if you had played your trick."

    The boy replied, "You have taught me a lesson which I'll never forget. Now I understand these words, which I didn't understand before: It is more blessed(神圣的)to give than to receive."