问题 填空题

写出下列反应的符号表达式,并在题后括号中注明反应的基本类型.

(1)混有氧气的氢气点火爆炸______(化合)反应;

(2)加热氯酸钾和二氧化锰制氧气______(分解)反应;

(3)铁丝在氧气中燃烧______

(4)氢气在氯气中燃烧生成氯化氢______.

答案

(1)混有氧气的氢气点火爆炸生成水,符号表达式:H2+O2

点燃
 H2O,由两种物质反应生成一种,属于化合反应;

(2)氯酸钾和少量二氧化锰混合加热生成氯化钾和氧气,反应物是一种,生成物是两种,属于分解反应.

符号表达式及其物质的化学式为:KClO3

MnO2
KCl+O2(分解反应);

(3)铁丝在氧气中燃烧能生成四氧化三铁,反应物是两种,生成物是一种,属于化合反应,

 符号表达式为及其物质的化学式:Fe+O2

点燃
Fe3O4 (化合反应);

(4)氢气在氯气中燃烧生成氯化氢,符号表达式:H2+Cl2

点燃
 HCl,由两种物质反应生成一种,属于化合反应.

填空题
阅读理解

Gossip moves so quickly that few people have time to cover their ears, even if they want to.

“I hate it when others gossip about me,” said Mandy Miraglia, 16, a high school student from California, “but to be honest, gossip about my friends makes me feel I am trusted and belong to the group.” Miraglia is not the only person feeling like that.

Gossip has long been looked down on as little more than nonsense and bad manners. But recent research has shown that gossip has many positive effects on your social life.

“There has been a trend among people to dislike gossip,” said David Sloan Wilson, Professor from the State University of New York in Binghamton, US, “but gossip appears to be a very important form of behavior in a group of friends, defining their group membership.”

For 18 months, Kevin Kniffin, from the University of Wisconsin, US, researched the behavior of 50 people. He found that gossip levels peaked when a sports team included a slacker, someone who regularly missed practices or showed up late. Other members of the team would soon start to joke about the slacker’s shortcomings behind his back, because they thought they were bad for the whole team.

Gossip about the mistakes of senior members helps newcomers rebuild their confidence after a failure.

It also helps relieve social and professional anxiety. Long-term studies show that people around the world devote from a fifth to two-thirds or more of their daily conversation to gossip, and men appear to be just as eager for gossip as women.

It is hard to judge gossip, but it is more powerful than you think.

小题1: The author would probably agree that______________.

A.gossip is bad manners

B.gossip has many good effects

C.gossip is somewhat like nonsense

D.gossip is more powerful than advice小题2: What does the underlined word “slacker” mean according to the context?

A.Someone who values the team benefit much.

B.Someone who does not do what they should well.

C.Someone who is active in sports.

D.Someone who shows no much interest in sports.小题3:Which of the following is NOT true according to the passage?

A.Gossip is a useful way of building group membership.

B.Gossip can possibly make someone confident.

C.Generally, women are fonder of gossip than men.

D.Actually, everyone gossips to some degree in their daily conversation.