题干

几种短周期元素的原子半径及主要化合价如下表:
元素代号
X
Y
Z
W
原子半径/pm
160
143
70
66
主要化合价
+2
+3
+5、+3、-3
-2
下列叙述正确的是                                      (  )

A:X、Y元素的金属性 X<Y

B:一定条件下,Z单质与W的常见单质直接生成2W2

C:Y的最高价氧化物对应的水化物能溶于稀氨水

D:一定条件下,W单质可以将Z单质从其氢化物中置换出来

上一题 下一题 0.0难度 选择题 更新时间:2017-07-10 12:38:50

答案(点此获取答案解析)

D

同类题5

阅读理解

    The right name is important in the business world. All you have to do is to think of the names for some of the products you buy every day and you'll agree that the name and the product are connected in everyone's mind.

    In many countries, successful trade or brand(商标)names are protected by law so that other companies cannot make the same product by copying. Businesses register(注册)a company or a product name with the government. In fact, more than 1,000 product and company names are registered every hour. Many companies spend a lot of money to find the right name for their products. A good example of this is in the car industry. Some successful names for cars have powerful associations(联系).The Ford Mustang and the Jaguar are only two examples of choosing the names of animals that are fast and strong.

    When a U.S. company decides to sell its product in another country, it has to make sure that the product name translates properly. When Coca-Cola introduced its soft drink to China it looked for the right name. It wanted a name that would do two things. One was to present its image in Chinese and the second was to be close to its first brand name-Coke. It took some efforts before finding the right word-which sounds similar and translates as "happiness in the mouth".  Asian company names are not new to the United States. The brand names of Samsung and Sony have been successful. Finding the right brand name is a big business. Asian companies that sell to foreign markets pay to find a name that will connect with its customers. There are even naming companies that offer help in inventing product names. These companies can charge(要价)up to $ 100,000 a word for their good names. But it's worth it. Successful companies know how important the right brand names are for their development.