问题 问答题

用数字和化学符号表示:

(1)2个氯原子______;    (2)铵根离子______;

(3)5个氮气分子______;  (4)硫酸铁中硫元素显+6价______.

(5)构成氯化钠的微粒是______和______.

答案

(1)根据原子的表示方法: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.因此2个氯原子表示为:2Cl;故答案为:2Cl;

(2)根据离子的表示方法: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.若表示多个该离子,就在其元素符号前加上相应的数字;因此铵根离子表示为:NH4+;故答案为:NH4+

(3)根据分子的表示方法:正确书写物质的化学式,表示多个该分子,就在其化学式前加上相应的数字,因此5个氮气分子表示为:5N2;故答案为:5N2

(4)根据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,因此硫酸铁中硫元素显+6价表示为:

+6
Fe2(SO4)3

故答案为:

+6
Fe2(SO4)3

(5)构成氯化钠的微粒是钠离子和氯离子,根据离子的表示方法,表示为:Na+、Cl-; 故答案为:Na+;Cl-

阅读理解

阅读理解。

     A study by St.. Louis University has found that a lovable dog named Sparky and a robotic dog,

AIBO, were about equally effective at reducing the loneliness of nursing home residents. The study

confirmed previous findings that dogs have a good effect on nursing home residents.

Dr. Andrew Smith led the Stanford University team that built a home-assistance robot. "If humans can

feel an emotional tie with robots, some day they could be not just our assistants, but also our

companions," he said.

     To test whether residents responded better to Sparky, a trained dog, or the Sony-made robotic dog,

researchers divided 38 nursing home residents into three groups at three long-term care centers in St.

Louis.

One group had weekly 30-minute one-on-one visits with Sparky; another group had similar visits with

AIBO; a control group had no contact with either dog. The groups' respective levels of loneliness were

tested by having them answer a number of questions at the beginning and near the end of the visits.

After two months, both groups that had contact with the dogs were less lonely and more attached. Most

of the elderly regarded Sparky, a 9-year-old dog, as an audience for their life stories, said investigator

Marian Banks.

     "He listened attentively, wagged his tail, and allowed them to pet him," said Banks, who adopted and

trained Sparky after finding him in a street behind her home seven years ago.

     Those who were together with AIBO took a little longer to warm to the robotic creature. Over time,

however, they grew comfortable with him, and petted and talked to him. He would respond by wagging

his tail, vocalizing, and blinking his lights..

     "AIBO is charming once you start to interact with him," said the study's author, Dr. William Banks,

" He's an attractive sort of guy. He gives a feeling of being personal, not just a robot."

1. Before the new study, it was known that ____.

A. robots were effective at reducing people's loneliness

B. robots could build close connection with humans

C. dogs could help get rid of old people's loneliness

D. dogs and robots were equally effective at reducing loneliness

2. Those who had contact with the robotic dog found that ___.

A. they didn't feel comfortable with it

B. it was hard for them to interact with it

C. they weren't comfortable with it at first

D. the robot's vocalizing and blinking confused them

3. The findings of the researchers tell us that___.

A. robots are better at caring for old people than nurses

B. robots can to some degree replace dogs as companions for old people

C. it's easy for people to become close with robots

D. every home will have a robot assistant one day

4. What would be the best title for the passage?

A. Robots Serve People Better Than Thought

B. No More Lonely Old Age with Emotional Robots

C. Advanced Technology Used to Cheer up the Elderly

D. Robots and Dogs Can Equally Cheer up the Elderly

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