阐述自然地理环境地域分异的尺度问题?

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问题:

阐述自然地理环境地域分异的尺度问题?

考点:地球科学自然地理学自然地理学题库
题型:问答题 简答题

(8分)钠、镁、铝是重要的金属元素,与我们的生活和生产关系密切。

(1)元素的性质特别是化学性质取决于元素原子结构。钠离子的电子排布式为_______,铝元素的原子结构示意图为_________。

(2)钠、镁、铝元素的阳离子半径由小到大的顺序是_____________(用离子符号表示)。在短周期中非金属性最强的元素位于第____周期____族。

(3)钠、镁、铝的单质及其化合物在某些性质上存在着递变规律。下列有关说法正确的是___________(选填编号)。

a.三种元素的金属性越强,金属单质的熔点就越高

b.其碱性按NaOH、Mg(OH)2、Al(OH)3顺序依次减弱

c.常温下都能与浓硝酸剧烈反应生成硝酸盐,但剧烈程度依次减弱

d.等质量的钠、镁、铝与足量稀硫酸反应生成氢气的物质的量依次增加

(4)1932年,美国化学大师Linus Pauling提出电负性(用希腊字母χ表示)的概念,用来确定化合物中原子某种能力的相对大小。Linus Pauling假定氟元素的电负性为4,并通过热化学方法建立了其他元素的电负性。第三周期主族元素的电负性如下:

元素NaMgAlSiPSCl
电负性0.91.21.51.82.12.53.0
从上表可以看出电负性的大小与元素非金属性的强弱关系是____________________;大量事实表明,当两种元素的χ值相差大于或等于1.7时,形成的化合物一般是离子化合物,根据此经验规律,AlBr3中的化学键类型应该是                

题型:问答题 简答题

制定《计量法》的目的,是为了保障()的统一和量值的准确可靠。

A.计量

B.单位

C.单位制

D.计量单位制

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阅读理解。

    In the past, when people had problems, they went to their families or friends to get advices. Today it is

possible to get advice from radio shows, TV programs and telephones hot lines, too. A hot line is a telephone

line that offers a direct way of getting in touch with advisers. Most hot lines are completely anonymous-

callers do not have to say their names or telephone numbers. Most hot lines are usually free, too.

    Callers do not have to pay for advice or the phone calls-even if the calls are long distance (距离). At some

hot lines, the advisers are volunteers (志愿者). Other hot lines pay their advisers for their work. Usually the

advisers are full-job people with years of education and experience, but sometimes, the advisers have only

taken a short class before starting to work on the hot line. All the advisers listen to people and help them solve

their problems.

1. A hot line is a telephone line _____. [ ]

A. that is hot

B. through which people get advice

C. whose number no one knows

D. through which callers take a short class

2. When people call the hot line advisers, they _____. [ ]

A. often give their names and telephone numbers

B. generally have to pay for the long distance calls

C. usually pay nothing for most of the calls and advice

D. always try to get in touch with the volunteer advisers

3. The advisers working at hot lines _____. [ ]

A. are not all paid

B. are all volunteers

C. all have years of education and experience

D. have all been trained for a short time

4. How do the hot line advisers work? [ ]

A. They do what the callers tell them to do

B. They accept the caller's advice

C. They give the callers advice

D. They go to the callers' houses to help them

5. The writer of the article seems to think that _____.[ ]

A. with hot lines people won't get advice from their families or friends

B. hot lines help the callers a lot

C. people had better pay for the advice and phone calls

D. the hot line advisers will solve all of the callers' problems

题型:问答题 简答题

( )石料与沥青的黏附性差。

A.酸性

B.碱性

C.中性

D.酸性、咸性

题型:问答题 简答题

窗口期最长的是()

A.CK、CK-MB

B.cTn

C.Mb

D.cTnl

E.MLC

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