题目内容

【题目】19世纪末，物理学家瑞利在研究中发现，从空气中分离得到的氮气密度，与从含氮物质制得的氮气密度有0.0064 kg/m3的差异，他没有放过这一发现，在化学家拉姆塞的合作下，经过十几年的努力，于1894年发现了空气中的氩气。下列说法正确的是________(填序号)。

①氩是一种化学性质极不活泼的气体；

②瑞利从空气中分离的氮气是纯净物；

③19世纪末以前，人们认为空气由氧气和氮气组成的；

④瑞利发现，从含氮物质制得的氮气密度大于从空气中分离的氮气的密度。

【答案】①③

【解析】

试题分析：①氩是稀有气体（惰性气体），化学性质极不活泼；

②瑞利从空气中分离的氮气中含稀有气体，不是纯净物；

③19世纪末以前，人们认为空气由氧气和氮气组成的；

④从含氮物质制得的氮气是纯净物，而从空气中分离的氮气还含有密度大于氮气的稀有气体。所以从含氮物质制得的氮气密度要小。

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【题目】B

Once there was a parrot on sale in a pet store. It was a beautiful red and blue bird. It sat on a perch in the middle of the store, so that everyone could see it when they came in. The owner was very proud of it and asked a high price for it.

One day a man went into the store. ＂That’s a beautiful bird,＂ he said to the pet store owner, ＂But why is it so expensive? Is it an unusual bird?＂

＂No, it’s not very unusual. It’s expensive because it can talk,＂ the pet store owner said.

＂I see. How can I make it talk?＂ the man asked.

The pet store owner asked him,＂Do you see those strings tied to each of the bird’s legs?＂

＂Yes,＂the man answered.

＂Well, you pull those strings,＂ the pet store owner told him. ＂That will make the parrot talk.＂

The man asked, ＂Do you mind if I try?＂

＂Not at all,＂ the pet store owner said.

The man walked up to the parrot and pulled the string on its left leg. The parrot said, ＂Good morning.＂

The man pulled the string on the parrot’s right leg. This time the parrot said, ＂How are you today?＂

＂That’s not very interesting, ＂ said the man. ＂Any parrot could do that.＂ Then he laughed, ＂But what would happen if I pulled both strings at the same time?＂

＂I’ll fall off my perch, youfool!＂ the parrot said.

【1】 The parrot was expensive because __________.

A. it was pretty beautiful B. it could talk with the people

C. it was a very unusual bird D. it was in the middle of the store

【2】The parrot would talk when __________.

A. people came into the pet store B. it was the pet store owner

C. people said it was beautiful D. people pulled the strings on its legs

【3】 Which is the first sentence that the parrot said to the man?

A. Good morning. B. How are you?

C. That’s wasn’t interesting. D. I’ll fall off my perch, you fool.

【4】 From the story we know the parrot was __________.

A. kind B. silly C. clever D. crazy

【5】The best title for the passage should be __________.

A. Unusual Parrot B. Parrot Talk C. Silly Man D. Clever Owner

【题目】下面关于内能的说法中，正确的是（ ）

A. 一个物体没有机械能，就没有内能

B. 一个物体可以没有内能，但一定有机械能。

C. 因为内能与温度有关，所以0℃的物体没有内能。

D. 一切物体都有内能

【题目】

【1】watch, Tom, in, evening, the, doesn’t, TV

____________________________.

【2】favorite, what, is, your, sport

____________________________?

【3】because, art, like, I, it, interesting, is

_____________________________.

【4】he, have, does, on, Monday, geography

_____________________________?

【5】music , subject , favorite , is , his

_____________________________.

【题目】

【1】a，v,e,h, _____

【2】e,t,n,n,s,i _______

【3】l,b,a,v,o,l,y,e, l,l________

【4】u,f,n ______

【5】o,u,s,n,d ______

【6】a,c,s,s,l _______

【7】a,e,l,t_____

【8】e,s,a,m_______

【9】i,w,h,t ________

【10】b,o,i,n,r,g_______

【题目】用符合题目要求的序号填空：

①氧气；②空气；③二氧化碳；④二氧化硫；⑤五氧化二磷；⑥四氧化三铁。

（1）通常状况下无色、无味的气体是________；

（2）有刺激性气味并且污染空气的气体是________；

（3）属于黑色固体的是________；

（4）支持燃烧的气体是________；

（5）属于白色固体的是________。

【题目】下列有关氧气性质的说法中错误的是( )。

A．氧气是一种化学性质比较活泼的气体

B．它能跟所有物质发生化学反应

C．在氧化反应中一般都有热量放出

D．氧气能供给呼吸，支持燃烧

【题目】实验测得某物质中只含有碳元素，则这种物质( )。

A．一定是金刚石或石墨中的一种

B．一定是木炭或活性炭中的一种

C．一定是碳元素的一种单质

D．可能是一种碳单质，也可能是几种碳单质组成的混合物

【题目】下列常见的盐在生产、生活中的用途不合理的是( )。

A．用亚硝酸钠腌制食品

B．碳酸钠广泛应用于玻璃、造纸、纺织和洗涤剂的生产

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