请认真阅读下面短文，并根据短文内容回答问题。 On December 23, 2008, Niu Niu held a piano concert at

我11岁了，用英语说是， I"m 11 years old.

Robby was 10 for his first piano lesson in my class.robby在10岁的时候第一次上我的钢琴课。

be11-yearoldboy=is/was11-yearoldboy是十一岁大之男孩。e.g.Heis11-yearoldboynow.他现在是个十一岁大之男孩。an11-year-oldboy一个十一岁大之男孩。e.g.An11-year-oldboycannotdothiscalculusyet.一个十一岁大的男孩还未能做微积分.

在英语中，表示年龄的词语组是“years old”，意思为“……岁”。而在写法上，有些地方需要注意一下的，即years old 和year-old因为years old表达的是“某人多少岁了”，而year-old则表示“多少岁的人”。所以，这就是years old和year-old的区别

艺人名称：City High唱片名称：《City High》出版公司：环球唱片 发行日期： 2001-9 曲目列表：1. Didn‘t Ya2. Three Way3. Why4. Song For You5. 15 Will Get You 206. Cat And Dogs7. Caramel8. Best Friends9. Sista10. What Would You Do11. So Many Things12. The Only One I Trust13. City High Anthem14. You Don‘t Know Me歌词 [Robby (Ryan)](What"s up my nigga?)Heh, chillin" yo(What"s up man, ya ready to go? Come on!)Naw yo, you just go ahead(What"s wrong with you man?)(Wifey got you buggin" again)Pshh, I just don"t understand, ya know(Understand what man? Huh?)She ain"t talkin" to me son(Word)Yo I need you to do me a favor yo(What?)You gotta call her homie(What"chu want me to call her for)You gotta tell her for me(Tell her what man)That I love her so strongly(Why don"t you just tell her yourself)Cause she won"t listen to me now(Damn)Without love in my heartI might as well be dead(Hold up, hold up, you ain"t gonna be killin" yourself nigga)So can you help me out?(I"m callin i"m callin)You"re the only one who cares[Ryan (Claudette)]Yo shortyI just got off the phone with RobbieHe told me to come talk to you(Yeah, bout what?)He said y"all having problemsAnd you left him, now he"s all confused(Man, so what?)Now girl why you buggin?You know you was made for himAnd him for youI ain"t trying to butt inI just wanna be a friendAnd he asked me to call you[1] - You gotta call her homieAnd tell her for meThat I love her stronglyShe won"t listen to meWithout love in my heartI might as well be deadPlease help me nowYou"re the only who caresYou gotta call her homieAnd tell her for meThat I"m really sorryShe won"t listen to meWithout love in my heartI might as well be deadPlease help me nowYou"re the only who cares[Ryan]Hmm, girl this thing has gone on, long enoughCan"t you seeHe don"t know the true reason that you left himBaby is cause of me, whoaHe would be real surprisedTo find that I"m the new apple of your eyeWhat kind of friend am I?To take advantage of - my best friend"s trust[Repeat 1][Claudette (Robby)]If you wanna knowWhy I did - what I did(Tell me why did you do it)I got tired of being aloneWhile you was out trickin"(Who told you I was trickin?)I guess female dogs can"t learn tricks tooYou see I"m not the bitch, baby payback isAnd what you did came back to you, oh

这里的11-year-old表示11岁的，当作形容词使用的。one 11-year-old boy 一个11岁的男孩。或者说The boy is 11 years old. 这个男孩11岁。

eleven years old

6-year-old放在名词前，做定语6 years old 放在系动词后，作表语

12year old

Jean Todt (born February 25, 1946) is a former executive director of Scuderia Ferrari, the Ferrari company"s Formula One constructor. On October 25, 2006, he was appointed as the company"s CEO. On March 18, 2008, Todt resigned as CEO and assumed a "special appointment" within the company"s racing department. He resigned this position one year later.On 23 October, 2009, he was elected as president of the FIA, motor sport"s world governing body. Todt, who succeeds Max Mosley, stood against Finland"s former world rally champion Ari Vatanen for the position.1.Life and careerTodt was born in the commune of Pierrefort in the Cantal department of France. His father was Polish Jew who escaped to France during World War II. His mother was French. Todt"s motorsport career began when he borrowed his father"s Mini Cooper S for a friend to drive in a rally. Todt soon became a rally driver himself. He moved to various driving roles in rally series, but decided his strength was as a co-driver; he continued as such with the Peugeot Talbot Sport rally team until his retirement from competition in 1981.2.Peugeot Talbot SportThe team moved Todt into a management-oriented position, charging him to organize the design and construction of the 205 Turbo 16 for the 1984 World Rally Championship season. After a slow start, the 205 won the world title in 1985 and 1986; other Todt-managed models continued to dominate, winning rally championships, hill climbs, and with the highly successful Peugeot 905, the Le Mans 24 hours and the World Sportscar Championship, into the 1990s. Peugeot, despite Todt"s continual urging, refused to enter the Formula One Championship, and when a position opened at the Ferrari F1 team, Todt took the opportunity in 1993.3.Scuderia FerrariJean Todt at Spanish GP 2001Todt was the first senior appointment of Ferrari president Luca di Montezemolo who had been placed in charge of a once legendary team which "had become something of a joke."The Todt/Montezemolo leadership hired Michael Schumacher in 1996, with whom came strategist Ross Brawn, and designer Rory Byrne. The Independent credited Todt with melding this combination "into a cohesive structure devoid of the polemics which were so rife."The fortunate combination produced a nearly-unbeatable team. Todt and Ferrari president Luca di Montezemolo have since been considered responsible for turning Ferrari from a has-been team, helpless without founder Enzo Ferrari, into the powerhouse it is today.Following much speculation as to FIA President Max Mosley"s impending retirement, rumors arose in 2004 to the effect that Todt would run for the office. Mosley commented that though Todt would make an excellent president, he was quite happy at Ferrari; however, it had long been assumed that when Michael Schumacher retired from F1, Todt would leave his job. In an apparent bid to maintain Todt"s loyalty, Ferrari president Luca di Montezemolo promoted Todt to the head of the entire Ferrari operation, including street car production.He remained as the Team Principal of the Scuderia F1 Team for one more season, and was replaced by Stefano Domenicali on 1 January 2008, however he still remained as CEO of Ferrari. On March 17, 2009, it was announced that Todt had resigned, leaving Ferrari completely.The French government has made Todt a Chevalier of its Legion d"Honneur. He was further honoured with the Grand Officier rank of the honour in January 2007.Also, in July 2006, Todt was given the official Malaysian royal title of "Datuk" by Sultan of Terengganu, which is the Malaysian equivalent of a British knighthood - he is now widely addressed in Malaysian media as Datuk Seri Jean Todt.4.FIA PresidencyAs of October 23, 2009, Jean Todt was elected president of the FIA, with 135 votes against 49 votes for ex-driver Ari Vatanen.5.Personal lifeOn September 28, 2005, Todt"s engagement to actress Michelle Yeoh was reported.Yeoh has subsequently denied the engagement. As recently as March 2007, Yeoh denied assertions as to an upcoming marriage. On July 31, 2008, Ms. Yeoh confirmed the rumor that she was engaged (to Jean Todt) during an interview with Craig Ferguson on CBS"s The Late Late Show.Todt joined the Malaysia My Second Home Programme(MM2H) in April 2009. On 13 May 2009, Jean Todt was named as the Tourism Malaysia"s Ambassador.Todt has a small role in the film Astérix at the Olympic Games.Todt"s son Nicolas is a manager of Formula One drivers including Ferrari incumbent Felipe Massa.

英语十岁是什么？

他9岁。（1）He"s nine years old. (2) He"s nine-year old.

【答案】【小题1】B【小题2】C【小题3】A【小题4】B【小题5】A【答案解析】试题分析：这篇文章讲的是11岁的男孩Hamad和他的绘画天赋，他将在这个周末在Llangollen"sGardeningShow举行第一次画展。【小题1】主旨题：从第一段的句子：An11-year-oldboywhohasbeencomparedtoSpanishImpressionist(印象派画家),thegreatPabloPicasso,可知这篇文章讲的是Hamad和他的绘画天赋，选B【小题2】细节题：从文章第三段的句子：Buthebegantopainthisfavouritefootballplayer,CristianoRonaldo,usingPicasso"strademarks(标志)—brightcoloursandimpressionisticforms.可知Hamad非常喜欢CristianoRonaldo，选C【小题3】细节题：从文章第三段的句子：Buthebegantopainthisfavouritefootballplayer,CristianoRonaldo,usingPicasso"strademarks(标志)—brightcoloursandimpressionisticforms.可知Hamad画的第一副CristianoRonaldo的画有明亮的色彩和印象派的形式，选A【小题4】猜词题：从第五段的句子：Theylikedthemverymuchandeveryonewaseagertobuy,sothefirstsixpaintingshavebeensnappedup.可知"snappedup"的意思是“很快销售”，选B【小题5】细节题：从文章第五段的句子：HehadtalentandIthoughtPicassohadbeenreborn."可知SteveTurner高度评价Hamad，选A考点：考查新闻报道类短文

我讨厌

A, C, D,

1. Many experts think pigs are ______ to train than dogs or cats.A. easier B. much easy C. more easily D. too easy2. Ginger can"t dance as ______ as Jasmine, but she still got the prize.A. beautifully B. more beautifully C. less beautifully D. the most beautifully3. Matt became so ______ when I dropped the coffee on her shirt, which made me quite upset.A. forgetful B. carefully C. angry 　D. sadly4. Often life is much ________ outside the big cities, as is true in other countries as well.A. slow B. slower C. slowest D. the slowest5. Mary looked _____ because she lost her new watch last week.A. friendly B. upset C. happy D. excited6. Mr Wang is usually the first one to come to work, but today Xiao Li came than he.A. early B. earliest C. earlier D. very early7. The beef tastes the pork. Please make yourself at home.A. as better as B. much better than C. the best than D. as well as8. I need _____ bananas to make fruit salad. Could you please buy some? A. few B. a few C. little D. a little9. The more you smile, the _______ will feel in your everyday life. A. happy B. happier C. happiest D. the happiest10. He has read many books on history, so it"s _______ for him to answer these questions.A. hard B. impossible C. serious D. easy11. When he heard a cry for help, he can run out as______ as he could.A. hardly B. finally C. quickly D. slowly12. If you save every day, you"ll be able to buy a mobile in a year.A. a little B. little C. a few D. few13. The black suitcase is the red one. I"ll take the red one.A. so expensive as B. much expensive than C. more expensive as D. much more expensive than14. The boy checked his test paper in order to get full marks.A. enough careful B. enough carefully C. careful enough D. carefully enough15. We feel so that China has sent its first space laboratory, Tiangong-1 into orbit successfully.A. exciting B. excited C. excite D. excitedly16Take a look at this photo. It"s the ________one I have ever taken.A.beautiful B. uglier C. more expensive D. prettiest17. The fish soup tasted so that the guests asked for more.A. bad B. terrible C. well D. good18. Mobile phones are very popular nowadays and they are_______ than before.A. cheap B. cheaper C. cheapest D. the cheapest19. It"s difficult to live in a foreign country，________if you don"t speak the languageA. importantly B. naturally C. especially D. usually20. The house price in Shanghai is __________ to become lower and lower in the coming years.A. politely B. possibly C. likely D. happily21. With the help of computers, writing does not seem so _________ as it used to be.A. difficult B. less difficult C. more difficult D. the most difficult 22. Do you think which means of transport is , the underground or the plane?A. safe B. safety C. safest D. the safest23. The roast beef tastes so . May I have one more piece, mum?A. well B. bad C. delicious D. terrible24. Among the earrings I choose pair because I didn"t bring enough money that day.A. cheap B. cheaper C. cheapest D. the cheapest25. Alice"s mother bought Alice a new dress. This beautiful dress made her look .A. quietly B. lovely C. politely D. gently26. My son likes reading stories. Now he can tell a story as as his sister.A. better B. best C. good D. well27. The film Tintin "s Adventure is , so it is welcomed by teenagers.A. amazing B. excited C. boring D. bored28. It"s said that the road we drove along just now is ________ in this area.A. busy B. busier C. busiest D. the busiest29. The film The Flowers of War is as as the one we saw last weekA. attractive B. more attractive C. most attractive D. the most attractive30. As soon as George heard the bad news, his face turned .A. red B. pale C. sadly D. happily31. Jenny likes the new neighborhood because people here are .A. friendly B. softly C. politely D. nicely32. Do you know of all the words we used in 2011 "hold" became in China?A. hot B. hotter C. hottest D. the hottest33. Tea is _____ drink in the world besides water.A. popular B. more popular C. most popular D. the most popular34. Steven completed the science test______ in our class yesterday.A. most quickly B. more quickly C. less quickly D. quickly35. The actress is at least 50, but she looks _______than she really is.A. very young B. much younger C. very old D. much older 36. Nowadays science fiction isn"t as ____________ as cartoons among teenagers. A. popular B. more popular C. less popular D. the most popular37. We are glad to see that Shanghai is developing _______ these years than ever before. A. quickly B. less quickly C. more quickly D. the most quickly38. The cheese cake tasted so ______ that the kids asked for more.A. delicious B. well C. bad D. badly39. —Why didn"t you enjoy the talk? —It was ________talk that I had ever listened to. A. the most interesting B. the least interesting C. more interesting D. 1ess interesting40. Guo Yue did quite _______ at the World Table Tennis Championship（锦标赛），but Zhang Yining did even ________.A. better; well B. well; well C. well; better D. better; better41. — Whose picture is better, Jack"s or Tom"s?— Both of them are good. I think Jack draws Tom. A. as good as B. as well as C. better than D. worse than42. It gets very here in summer. A. cool B. cold C. warm D. hot43. Be ________, and you will do well in the English exam.A. careful B. polite C. sure D. friendly44. Lin Tao is good at all the subjects at school, _________English.A. really B. mostly C. especially D. exactly45. —The coat is too expensive. —Look, here"s another one. It"s________ and nicer. 结：

（1）根据相对分子的质量（式量）为组成分子的各原子的相对原子质量之和，可得硝酸铵的相对分子质量为14×2+4+16×3=80．（2）根据化合物中各元素质量比=各元素的相对原子质量×原子个数之比，可得硝酸铵中氮、氢、氧元素的质量比为（14×2）：（1×4）：（16×3）=7：1：12．（3）NH4NO3中氮元素的质量分数为：14×280×100%=35%．（4）100千克硝酸铵中含氮元素：100kg×35%=35kg；（5）含35kg氮元素需要碳酸氢铵的质量为：35kg÷1414+1×5+12+16×3×100%=197.5kg；（6）该袋化肥中氮元素的质量分数为：90%×35%=31.5%．故答案为：（1）80；（2）7：1：12；（3）35%；（4）35；（5）197.5；（6）31.5%．

硝酸根的化学式为：NOu2083u207b。硝酸根是指硝酸盐的阴离子，化学式为NOu2083u207b，硝酸根为－1价，其中N为最高价＋5价。用途硝酸银实验室中用于检验氯离子，因为银离子和氯离子能结合成不溶于酸的白色沉淀氯化银。一般还与稀硝酸配合用于检验。在有机化学中，硝酸根可以用于生成硝酸酯（RONO2），比如卤代烃与硝酸银反应就可以生成卤化银沉淀和硝酸酯。硝酸钠常见的化肥。硝酸铵（NHu2084NOu2083）简称硝铵，常见的化肥。硝酸钾常见的复合肥料。

加权平均值即将各数值乘以相应的权数，然后加总求和得到总体值，再除以总的单位数。举例：下面是一个同学的某一科的考试成绩：平时测验 80， 期中 90， 期末 95学校规定的科目成绩的计算方式是：平时测验占 20%期中成绩占 30%期末成绩占 50%这里，每个成绩所占的比重叫做权重。那么，加权平均值 =( 80*20% + 90*30% + 95*50% )/(20%+30%+50%）=90.5权调和平均数适用于分组资料的计算，其计算公式为：平均数=（M1+M2+…+Mn）/(M1/X1+M2/X2+…+Mn/Xn)=∑Mi/∑(Mi/Xi)具体计算方法如下：（1）先计算出各个变量值的倒数，即1/X；（2）计算上述各个变量值倒数的算术平均数，即[∑(1/X)]/n;（3）再计算这种算术平均数的倒数，即n/[∑(1/X)]，就是调和平均数。

A、由硝酸铵的化学式为（NH4NO3）可以看出，它每个分子含有2个氮原子、4个氢原子、3个氧原子，共9个原子，故A错误；B、根据硝酸铵的化学式可知，硝酸铵的相对分子质量=14×2+4+16×3=80，故B错误；C、根据硝酸铵的化学式（NH4NO3）可知，其中氮、氢、氧三种元素的质量比═（14×2）：（1×4）：（16×3）=7：1：12，故C错误；D、硝酸铵中N元素的质量分数为=14×280×100%=35%，故D正确．故选D．

作用是被评价对象的不同侧面的重要程度的定量分配。在计算加权平均数时，常用权数来反映对应的数据的重要程度：权数越大的数据越重要。1、权的意义权有两种意义：①数据出现的个数；②数据所占的百分比。权数越大的数据在总体中所占的比例越大，它对加权平均数的影响也越大。2、权的定义“权”指的是一个比例和所占分数，加权平均值即将各数值乘以相应的权数，然后加总求和得到总体值，再除以总的单位数。加权平均值的大小不仅取决于总体中各单位的数值（变量值）的大小，而且取决于各数值出现的次数（频数）。由于各数值出现的次数对其在平均数中的影响起着权衡轻重的作用，因此叫做权数。因为加权平均值是根据权数的不同进行的平均数的计算，所以又叫加权平均数。扩展资料1、在日常生活中，人们常常把“权数”理解为事物所占的“权重”。比如现在有一年级学生一个，两年级学生一个，三年级学生两个，我们就说一年级学生权是1/4，三年级学生权是2/4。某一指标的权重是指该指标在整体评价中的相对重要程度。加权平均数是不同比重数据的平均数，加权平均数就是把原始数据按照合理的比例来计算。若 n个数中，x1出现f1次，x2出现f2次，…，xk出现fk次，那么(x1f1 + x2f2 + ... xkfk)/（f1 + f2 + ... + fk） 叫做x1，x2，…，xk的加权平均数。f1，f2，…，fk是x1，x2，…，xk的权.。2、加权平均数与算术平均数加权平均数与算术平均数类似，不同点在于，数据中的每个点对于平均数的贡献并不是相等的，有些点要比其他的点更加重要。加权平均数的概念在描述统计学中具有重要的意义。

简单算术平均数是在一组数据中所有数据之和除以数据的个数，如将各个地块的小麦产量直接相加得到总产量，再除以总亩数，得到平均亩产量。加权算术平均数是将变量乘权数求出标志总量，把权数相加求出总体总量，然后用前者除以后者，它适用于对分组的统计资料计算平均数。如将各个地块的产量按不同产量水平分成若干组，先将各组产量乘以各组的地块数求出各组的总产量后，相加求得全部地块的总产量，再除以地块总数，这样计算的平均亩产量称为加权算术平均数。算术平均数的优点是利用了所有数据的特征。但它也有不足之处，正是因为它利用了所有数据的信息，容易受极端数据的影响。扩展资料注意事项：在使用平均指标时，既要关注总量平均数，也应关注分类指标平均数，这样有助于我们正确使用平均数，从而进行比较分析。例如在使用居民消费价格指数（CPI）时，既要运用CPI总指数，也要综合使用食品、衣着等大类指标，有时候还要使用粮食、肉禽等具体小类商品的指数。

NH4NO3和NH4CI

是两个不同的颗粒呀：NH4+ NO3-

【答案】：C大小的因素有两个：①各组标志值的大小；②权数的影响。权数对算术平均数的影响，不取决于权数本身数值的大小，而是取决于作为权数的各组次数占总体次数的比重的大小。各组次数占总体次数的比重是计算加权算术平均数的实质权数。

nh4no3

NH4NO3

1、硝酸铵溶于水的化学方程式：NH4NO3+H2O=(可逆)NH3.H2O+HN03。 2、硝酸铵（NH4NO3）是一种铵盐，呈无色无臭的透明晶体或呈白色的晶体，极易溶于水，易吸湿结块，溶解时吸收大量热。受猛烈撞击或受热爆炸性分解，遇碱分解。是氧化剂，用于化肥和化工原料。

加权算术平均数和加权调和平均数的区别和联系加权算术平均数一般用在未知分子的情况下,即总体标志总量未知.调和算术平均数一般用在未知分母的情况下,即总体单位数未知

硝酸铵化学式为NH4NO3，铵根离子中氮元素的化合价为-3，硝酸根离子中氮元素化合价为+5。

加权平均值即将各数值乘以相应的权数，然后加总求和得到总体值，再除以总的单位数。举例： 下面是一个同学的某一科的考试成绩： 平时测验 80， 期中 90， 期末 95 学校规定的科目成绩的计算方式是： 平时测验占 20% 期中成绩占 30% 期末成绩占 50% 这里，每个成绩所占的比重叫做权重。那么， 加权平均值 =( 80*20% + 90*30% + 95*50% )/(20%+30%+50%）=90.5 权调和平均数 适用于分组资料的计算，其计算公式为： 平均数=（M1+M2+…+Mn）/(M1/X1+M2/X2+…+Mn/Xn)=∑Mi/∑(Mi/Xi) 具体计算方法如下： （1）先计算出各个变量值的倒数，即1/X； （2）计算上述各个变量值倒数的算术平均数，即[∑(1/X)]/n; （3）再计算这种算术平均数的倒数，即n/[∑(1/X)]，就是调和平均数。

HNO3

你首先要明白权是什么意思。字义上讲，权就是秤砣，他是用来横来物体重量的。所以，某数权越高，他占得比重就越大，越影响结果。比如某学期你期中考试80分，期末考了90分，那么你两次考试的算术平均分就是85分。但是我们觉得期末考试比较重要，他应该占平均分的60%，期中考试占40%，那么两次考试的加权平均数就是80*40%+90*60%=86，比算数平均大，因为权重大的分数高，如果期中考试占40%而期末占60%那么加权平均就是80*60%+90*40%=84，比算数平均小。其实算术平均数就是认为每个数占得权重一样大，比如上面的例子就是期中考试跟期末考试一样重要各占50%，80*50%+90*50%=85。所以加权平均跟算数平均究竟哪个大，主要是看高于平均数的大数占得权重大小（是否高于50%）

1. 绝对权数平均：（1000*12%+2000*10%+1500*7%+2800*10.5%）÷7300=9.85%2. 相对权数平均：（12%+10%+7%+10.5%）÷4=9.875%扩展资料：Yi代表不同时期的观测值(i=1，2，…，n)；n代表总体中的数据点数；Wi代表各个观察值对应的权数，Wi在0到1之间，即0≤Wi≤1。加权算术平均法是算术平均法的一般形式，即权数都相同时亦可用此公式形式。但权数都相同时。还是用简单算术平均法进行计算更简捷。参考资料来源：百度百科-加权算术平均法

硝酸铵的化学式怎么写？硝酸铵的化学式为NH4NO3。

Weightedaverage加权平均数是不同比重数据的平均数，加权平均数就是把原始数据按照合理的比例来计算，若n个数中，x1出现f1次，x2出现f2次，…，xk出现fk次，那么(x1f1+x2f2+...xkfk)÷（f1+f2+...+fk）叫做x1，x2，…，xk的加权平均数。f1，f2，…，fk是x1，x2，…，xk的权.其中，算术平均数是加权平均数的一种特殊形式（它特殊在各项的全相等），当实际问题中，当各项权不相等时，计算平均数时就要采用加权平均数，当各项权相等时，计算平均数就要采用算数平均数。两者不可混淆。公式：x拔=（x1f1+x2f2+...xkfk）/n，其中f1+f2+...+fk=n，f1，f2，…，fk叫做权。通过数和权的成绩来计算例子你的小测成绩是80分，期末考成绩是90分，老师要计算总的平均成绩，就按照小测40％、期末成绩60％的比例来算，所以你的平均成绩是：80×40％+90×60％＝86学校食堂吃饭，吃三碗的有χ人，吃两碗的有y人，吃一碗的z人。平均每人吃多少？(3×χ+2×y+1×z)÷(χ+y+z)这里x、y、z分别就是权数值，“加权”就是考虑到不同变量在总体中的比例份额。=============================当一组数据中的某些数重复出现几次时，那么它们的平均数的表示形式发生了一定的变化.例如，某人射击十次，其中二次射中10环，三次射中8环，四次射中7环，一次射中9环，那么他平均射中的环数为（10×2+9×1+8×3+7×4）÷10=8.1这里，7，8，9，10这四个数是射击者射中的几个不同环数，但它们出现的频数不同，分别为4，3，l，2，数据的频数越大，表明它对整组数据的平均数影响越大，实际上，频数起着权衡数据的作用，称之为权数或权重，上面的平均数称为加权平均数，不难看出，各个数据的权重之和恰为10.在加权平均数中，除了一组数据中某一个数的频数称为权重外，权重还有更广泛的含义.比如在一些体育比赛项目中，也要用到权重的思想.比如在跳水比赛中，每个运动员除完成规定动作外，还要完成一定数量的自选动作，而自选动作的难度是不同的，两位选手由于所选动作的难度系数不同，尽管完成各自动作的质量相同，但得分也是不相同的，难度系数大的运动员得分应该高些，难度系数实际上起着权重的作用.而普通的算术平均数的权重相等，都是1，（比如，3和5的平均数为4）也就是说它们的重要性相同，所以平均数是特殊的加权平均数.

硝酸铵做农药？为所未闻

硝酸铵的结构是：硝(左右结构)酸(左右结构)铵(左右结构)。硝酸铵的结构是：硝(左右结构)酸(左右结构)铵(左右结构)。拼音是：xiāosuānǎn。硝酸铵的具体解释是什么呢，我们通过以下几个方面为您介绍：一、词语解释【点此查看计划详细内容】硝酸铵是一种铵盐，化学式为NH4NO3，呈无色无臭的透明晶体或白色晶体，极易溶于水，易吸湿结块，溶解时吸收大量热。关于硝酸铵的成语尖酸刻薄甜酸苦辣酸文假醋拈酸吃醋拈酸泼醋透骨酸心狗恶酒酸关于硝酸铵的词语硝云弹雨甜酸苦辣狗猛酒酸攻苦茹酸尖酸刻薄透骨酸心寒心酸鼻拈酸吃醋硝烟弹雨狗恶酒酸关于硝酸铵的造句1、低成本和优性能的无梯粉状硝铵炸药是工业炸药发展的趋势之一，其中硝酸铵自敏化是关键的技术途径。2、西北大学化学系教授谢钢告诉中国青年报记者，硝酸铵是制造炸药的原料，本身也是一种氮肥。3、这样在电镀后再在硝酸和硝酸铵溶液中或在硝酸和铬酸溶液中退除铜镍镀层，由于铬层不受侵蚀，仍能维持不变。4、另一方面，硝酸铵与强还原剂混合时，又有很强的可爆炸性，所以同时又是工业炸药的原料之一。5、膨化硝酸铵自敏化理论是基于热点学说。点此查看更多关于硝酸铵的详细信息

NH4·（阴离子）

M=14+1*4+14+16*3N:H:O=14*2:1*4:16*3N%=28/80

NH4NO3+NaOH===(加热）NaNO3+NH3(气体符号)+H2O

硝酸铵的读音是：xiāosuānǎn。硝酸铵的拼音是：xiāosuānǎn。结构是：硝(左右结构)酸(左右结构)铵(左右结构)。硝酸铵的具体解释是什么呢，我们通过以下几个方面为您介绍：一、词语解释【点此查看计划详细内容】硝酸铵是一种铵盐，化学式为NH4NO3，呈无色无臭的透明晶体或白色晶体，极易溶于水，易吸湿结块，溶解时吸收大量热。关于硝酸铵的成语尖酸刻薄拈酸泼醋拈酸吃醋狗恶酒酸酸文假醋透骨酸心甜酸苦辣关于硝酸铵的词语硝烟弥漫硝云弹雨甜酸苦辣攻苦茹酸穷酸饿醋狗恶酒酸硝烟弹雨透骨酸心拈酸吃醋拈酸泼醋关于硝酸铵的造句1、膨化硝酸铵自敏化理论是基于热点学说。2、对防止粉状硝酸铵炸药的吸湿结块将起重要作用。3、西北大学化学系教授谢钢告诉中国青年报记者，硝酸铵是制造炸药的原料，本身也是一种氮肥。4、另一方面，硝酸铵与强还原剂混合时，又有很强的可爆炸性，所以同时又是工业炸药的原料之一。5、简述硝酸铵钙在农作物种植上的施用效果与市场前景。点此查看更多关于硝酸铵的详细信息

NH4NO3

简单分析一下，答案如图所示

1、硝酸铵的化学式是NH4NO3。2、纯净的硝酸铵是无色无臭的透明结晶或呈白色的小颗粒结晶，与碱反应有氨气生成，且吸收热量。有潮解性，易结块。易水同时吸热，还易溶于丙酮、氨水，微溶于乙醇，不溶于乙醚。3、硝酸铵受热分解温度不同，分解产物也不同。在110°C时：NH4NO3→NH3+HNO3。在185～200°C时：NH4NO3→N2O+2H2O。

加权算术平均数是将各组标志值乘以相应的各组单位数或权数求出各组标志总量,然后将其加总求得总体标志总量,同时把各组单位数或对数相加求出总体单位总量,最后用总体标志量除以总体单位总量.加权算术平均数公式:x(bar)=∑x(i)f(i)/∑f(i),f(i)是下标,：∑是求和比如:股票A,1000股,价格10；股票B,2000股,价格15； 那么,加权算术平均 = (10 x 1000 + 15 x 2000) / (1000 + 2000) = 13.33

硝酸铵的化学式：硝酸铵是一种铵盐，呈无色无臭的透明晶体或呈白色的晶体，极易溶于水，易吸湿结块，溶解时吸收大量热。受猛烈撞击或受热爆炸性分解，遇碱分解。是氧化剂，用于化肥和化工原料。1659年，德国人J.R.格劳贝尔首次制得硝酸铵。19世纪末期，欧洲人用硫酸铵与智利硝石进行复分解反应生产硝酸铵。扩展资料：硝酸铵属于易爆品，福建省曾制定硝酸铵类物品管理办法：根据《硝酸铵类物品管理办法》第三条　严格省内硝酸铵类物品生产、销售、使用管理，严禁利用硝酸铵、农用硝酸铵及硝酸铵复混肥非法制造爆炸物品。硝酸铵应纳入民用爆炸物品管理范畴，严格执行销售、购买许可制度，并加强流向监管。硝酸铵未经改性处理，不得直接作为化肥使用。改性处理后制成的农用硝酸铵和硝酸铵复混肥（硝酸铵含量超过50%的，下同），应强制进行抗爆性能检测，检测合格的方可销售、使用；不合格的，一律不得作为农用化肥销售、使用。参考资料来源：百度百科——硝酸铵

硝酸铵化学式是：NH4NO3。硝酸铵，是一种铵盐，呈白色结晶性粉末，极易溶于水，易吸湿结块，溶解时吸收大量热，是一种氧化剂，受猛烈撞击或受热爆炸性分解，遇碱分解，主要用作肥料及工业用和军用炸药。并可用于杀虫剂、冷冻剂、氧化氮吸收剂，制造笑气、烟火等。纯硝酸铵在常温下是稳定的，对打击、碰撞或摩擦均不敏感。但在高温、高压和有可被氧化的物质（还原剂）存在及电火花下会发生爆炸，硝酸铵在含水3%以上时无法爆轰，但仍会在一定温度下分解，在生产、贮运和使用中必须严格遵守安全规定。硝酸铵是极其钝感的炸药，比安全炸药C4更为钝感。一支工业8#雷管（起爆C4只是用6#就可以了）都不足以起爆混合了敏化剂的硝酸铵。硝酸铵是最难起爆的硝酸炸药，撞击感度是：50kg锤，50cm落高，0%爆炸。相比起著名炸药硝化甘油的200g锤，20cm落高，100%爆炸的感度，可见硝酸铵的钝感。而且硝酸铵一旦溶于水，起爆感度更是大大下降，根本是人力不可能撞击引爆的。

硝酸铵的化学式为NH4NO3。硝酸铵是一种无色晶体，其分子由NH4+和NO3-的离子配位形成。因此硝酸铵的化学式为NH4NO3。硝酸铵是一种重要的氮肥，也可用作爆炸药以及烟火的氧化剂。硝酸铵可由铵盐和硝酸反应制得，同时也是空气中的重要氮源。由于硝酸铵易潮解和爆炸性很强，因此在贮存和使用过程中需要注意保持环境干燥，避免与易燃物接触，并采取必要的安全措施。

　　1、硝酸铵的化学式为NH4NO3。 　　2、硝酸铵属于铵盐的一种，不具有颜色，也没有任何的气味，呈现为白色的晶体状态，能够快速的溶于水中，不过它的状态属于不稳定的那种，只要是受到猛烈的撞击或者是受到高温之时，它都很容易发生爆炸，从而导致事故的出现。