按要求写出下列化学名称或化学用语 (1)2个氮原子______; (2)3个碳酸

题型:问答题

问题:

按要求写出下列化学名称或化学用语

(1)2个氮原子______;

(2)3个碳酸根离子______;

(3)NH4+______;

(4)硫酸亚铁中铁元素的化合价为正2价______;

(5)科学家最新研究发现,碳70分子由70个碳原子构成,呈橄榄球状,在一定条件下吸收可见光后可高效杀灭癌细胞.则碳70分子的化学式为______.

考点:化学式的写法和意义
题型:问答题

______不能视为现金或现金等价物。

A.3年定期存款

B.货币市场基金

C.一幅名画

D.活期存款

题型:问答题

Long bus rides are like television shows .They have a beginning ,a Middle and an end –with commercials thrown in every three or four minutes .The commercials are unavoidable .They happen whether you want them or not .Every couple of minutes a billboard glides by outside the bus window . “buy super clean toothpaste”. “Drink Good’n Wet Root Beer .””Fill up with Pacific Gas .”Only if you sleep ,which site equal to turning the television set off ,are you spared the unending cry of “You Need It ! Buy It Now !” The beginning of the ride is comfortable and somewhat exciting ,Even if you’ve traveled that way before .usually some things have changed-new houses ,new buildings ,sometimes even a new road .The bus driver has a style of driving and it’s fun to try to figure it out the first hour or so . If the driver is particularly reckless or daring ,the ride can be an thrilling as a suspense story .Will the driver pass the truck in time Will the driver move into the right or the left –hand lane After a while,of course,the excitement dies down .sleeping for a while helps pass the middle hours of the ride .Food always makes bus rides more interesting .But you’ve got to be careful of what kind of foodyou eat .Too much salty food can make you very thirsty between stops. The end of the ride is somewhat like the beginning .You know it will soon be over and there’s a kind of expectation and excitement in that .The seat ,of course ,has become harder as the hours have passed.By now you’ve sat with you legs crossed ,with your hands crossed behind your head .the end comes just at the right time . There are just no more ways to sit.

What is the purpose of this passage ()

A.To give the write’s opinion about long bus trips

B.To persuade you to take a long bus trip

C.To explain how bus trips and television shows differ

D.To describe the billboards along the road

题型:问答题

一定量的氢气与一定量的氯气反应,所得混合物用100ml 3.00mol/L的NaOH溶液(密度为1.2g/ml)恰好完全吸收,测得溶液中含有NaClO的物质的量为0.05 mol(溶液中只含NaCl和NaClO两种溶质)。则下列有关说法不正确的是 [ ]

A.原NaOH溶液的质量分数为10.0%

B.所得溶液中Cl-的物质的量为0.25 mol

C.参加反应的氢气的物质的量为0.1 mol

D.所用氯气和参加反应的氢气的物质的量之比为2﹕3

题型:问答题

某常减压装置各物料与原油换热量为200GJ/h,用于发汽热量为10GJ/h,用于采暖热量为5GJ/h,空冷热量为40GJ/h,水冷5GJ/h,求热回收率。

题型:问答题

泡沫灭火器在扑救()火灾时,应将射流对准燃烧最猛烈处。

A.固体物质

B.气体

C.带电设备

D.轻金属

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