问题 填空题

按要求写出数字和符号:(1)3个硝酸根离子       ,(2)+2价的铁元素___     ____,(3)人体缺__  __ _元素易得佝偻病,(4)侯氏联合制碱法中的“碱”是          

答案

(1)3NO3- (2)Fe (3)Ca  (4)Na2CO3

(1)1个硝酸根离子含有1个氮原子和3个氧原子且带有1个单位的负电荷,表示原子团中原子个数的数字写在原子团符号中元素符号的右下角,因此硝酸根的符号表示为NO3;表示离子所带电荷数的数字写在原子团符号的右上角,且数字在前,正负号在后,因此硝酸根离子表示为NO3-;表示离子个数的数字写在离子符号的前面,因此3个硝酸根离子表示为3NO3-

(2)元素化合价的表示方法:确定出化合物中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+2价的铁元素可表示为:+2

Fe.

(3)人体缺少钙元素会导致青少年患佝偻病、老年人患骨质疏松症等.根据元素符号的书写方法,一大二小,钙元素可表示为:Ca;

(4)侯氏制碱法制的的碱是指生活中的纯碱,成分为碳酸钠,化学式为Na2CO3

单项选择题 A1型题
阅读理解

    Michael was a farmer in Texas.His parents moved to the USA from Ireland in the 1940’s, and they became very rich.Michael decided to go back to Ireland to meet his old grandfather, who was still living on the same farm.

Michael booked his ticket,flew to Shannon airport,hired a car and drove to the small village where his parents had been born.He asked for directions to the Ohagan farm,and in the end he drove up a bumpy path.He was shocked by what he saw:a small field,and in the middle of it was an old house,which looked as if it was falling down.Animals were wandering in and out of the front door,and on the porch an old man was smoking a pipe.

“Are you Mr. Ohagan?”asked Michael。

“Yes,”replied the old mall.

“I'm your grandson,Michael,”said Michael.

“A--ha,”replied the old man.

“Is this your farm?”asked Michael.

“Yes,all the way to the wall over there,”said the old man.

Michael was astonished.“Grandfather,”he said,“I have a farm in Texas.I can get into my car and drive all day and I still haven’t reached the end of the farm.”

“Yes,”said his grandfather.“I used to have a car like that.”

小题1:Michael’s parents _______.

A.still lived in Ireland alone

B.owned a small farm in Texas

C.returned to their birthplace

D.were Irish immigrants(移民)in America小题2:Which of the following shocked Michael?

A.The farm was small

B.The old house looked like his own.

C.Living conditions were poor in the fields.

D.Animals were free in the fields.小题3:The old man _______.

A.owned a small farm, which extended only to the wall not far away

B.had so large a farm that he couldn’t cover it in a day

C.hadn’t his modern car any longer

D.used to have as good a car as his grandson’s小题4:Which of the following is TRUE?

A.Michael owned a large farm in Ireland.

B.Michael’s car was in such poor condition that it couldn’t reach the end of the farm within a day.

C.Michael’s farm was too large for a car to reach its end in a day.

D.Michael didn’t know what to say to his grandfather小题5:From“I used to have a car like that”,we can see that________.

A.the old man really had a car like that

B.the old man knew his son’s farm in the US was quite large

C.the old man misunderstood what Michael said

D.the old man wanted to buy a car like that