问题 填空题

用化学用语填空:

2个氧原子______;3个氮分子______;铵根离子______;标出硫酸铁中铁的化合价______.

答案

(1)原子的表示方法就是用元素符号来表示一个原子,表示多个该原子,就在其元素符号前加上相应的数字.所以2个氧原子,就可表示为 2O,故答案为:2O.

(2)分子的表示方法:正确书写物质的化学式,如氮分子是双原子分子,可表示为:N2,表示多个该分子,就在其化学式前加上相应的数字,所以3个氮分子可表示为3N2.故答案为:3N2

(3)离子的表示方法:在表示该离子的元素符号右上角,标出该离子所带的正负电荷数,数字在前,正负符号在后,带1个电荷时,1要省略.表示多个该离子,就在其元素符号前加上相应的数字.但铵根离子是由多个原子组成的离子,整体带1个单元位的正电荷,表示为NH4+,所以答案为NH4+

(4)元素化合价的表示方法:化合物中确定所要标出的元素的化合价,然后在其化学式该元素的上方用正负号和数字表示,正负号在前,数字在后,所以硫酸铁中铁的化合价为+3价,故硫酸铁中铁的化合价为+3价可表示为:

+3
Fe
2(SO43.故答案为:
+3
Fe
2(SO43

单项选择题
阅读理解

If music makes you smarter and exercise helps you to think, surely exercising to music can turn you into an intelligent person.

A team of scientists from Ohio State University did experiments on 33 volunteers who were getting better from heart disease following operation. They found that people who exercised while listening to Italian musician Antonio Vivaldi’s “The Four Seasons” did much better on language ability tests than without music.

“Facts suggest that exercise improves the learning ability of people with heart disease,” said the psychologist Charles Emery, who led the study. “And listening to music is thought to enhance understanding. We just wanted to put the two results together,” he added.

The volunteers said they felt better emotionally and physically after working out with or without the music. But their improvement on the test doubled after listening to music during exercise. Scientists have proved that music can be good for health, education and well-being. It helps reduce stress, sadness and nervousness; encourages relaxation or sleep; wakes up the body and improves memory and thoughts.

In medical fields, music is used widely for patients who have had head hurts before and after operation. “The Four Seasons” was used because of its moderate tempo(舒缓的节拍)and positive results in earlier research. “Exercise seems to cause positive changes in the nervous system(神经系统) and these changes may have a direct result on learning ability,” Emery said.

Scientists have been studying the results of music on understanding since the early 1950s. By 2000, psychologists were using Mozart’s music, especially his violin pieces, to help children with speech disorders. Mozart was chosen because his music is not overexciting and has clear structures. A study showed students who listened to Mozart went on to score higher marks in an intelligence test. With important exams drawing near, your parents will not probably allow you to listen to music. But perhaps now you have good reasons to argue with them.

小题1:The underlined word enhance can be replaced by ______.

A.impress

B.improve

C.provide

D.produce小题2:The text mainly tells us that _____.

A.music and exercise lead to relaxation or sleep

B.33 volunteers work on music in medical fields

C.exercising to music makes people healthy and bright

D.scientists give suggestions on choosing music to exercise to小题3:It can be learned from the last paragraph that ______.

A.you are supposed to follow your parents’ words

B.students should not listen to music before exams

C.you have some good reasons to exercise to music

D.music might help you to get higher grades in tests小题4:Which of the following statements is true?

A.Exercise seems to cause negative changes without music.

B.Exercise reminds people with head hurts of what they’ve learned.

C.Scientists often use Mozart’s music, for it is not too exciting.

D.“The Four Seasons” is used to help children with speech disorders.