题干

物质的变化会受到诸多因素的影响,请根据下列变化的现象或结果的差异以及题给示例,说出相应的影响因素。

现象或结果的差异

影响因素

示例:生铁容易锈蚀,而钢则不易锈蚀。

物质的组成

①澄清石灰水中通入适量的二氧化碳后会变浑浊,但持续通入二氧化碳后浑浊又会变澄清。

____


②一氧化碳能将红棕色的氧化铁还原成黑色铁粉,二氧化碳则不能。

____


③二氧化碳通入水中后能和水反应生成碳酸,在绿色植物的叶绿素内二氧化碳和水却能转化为葡萄糖和氧气。

____


④石灰石粉末和稀盐酸的反应速率大于块状石灰石和稀盐酸的反应速率。

____


上一题 下一题 0.0难度 选择题 更新时间:2014-05-09 12:48:37

答案(点此获取答案解析)

反应物的量,分子的构成,反应条件,反应物之间的接触面积

同类题1

阅读理解

    Hundreds of years ago, news was carried from place to place by people on foot or by horse. It took days, weeks and sometimes months for people to receive news. Now it is possible to send words and pictures around the world in seconds(秒). Billions of people learn about news stories of their own country and all over the world every day, either by watching TV or reading newspapers. Newspapers have been an important part of everyday life since the 18th century. Many countries have hundreds of different newspapers. How do newspaper editors(编辑) decide which news stories to print (印刷)? Why do they print some stories and not others? What makes a good newspaper story?

    Firstly, it is important to report new stories. TV stations can report news much faster than newspapers. Yet, newspapers give more about the same story. They may also look at the story in another way, or they may print completely (完全地) different stories to those on TV.

    Secondly, a news story has to be interesting and unusual. People don't want to read stories about everyday life As a result, many stories are about some kind of danger and seem to be "bad" news. For example, newspapers never print stories about planes landing safely, instead they print stories about plane accidents.

    Another factor(因素) is also very important in many news stories. Many people are interested in news in foreign countries, but more prefer to read stories about people, places and events (事件) in their own country. So the stories on the front page in Chinese newspapers are usually very different from the ones in British, French and American newspapers.