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什么叫做元素的最高价态?每个元素的最高价态都是8价吗? my favourite place快急5句就够了 This is Peter speaking.Who' this?问对方不应该是Who's that?全文是A:Hello.B:Hello.May I speak to Peter,please?A:This is Peter speaking.Who' this?（就这句话怎么回事）B:This is Jack. 以Let' s Do Something to Save Our Environment英语作文要求1只有一个地球2主要问题.污染,疾病,灾难3停止污染,保护大自然80-100字可适当发挥 in contrast 和 by contrast的区别 有没有化合价为负的金属元素啊? 怎样判断非金属元素的最高价态和最低价态RT我学化学没多久，对元素周期什么的不太了解，能直白点说吗 高中常见短周期,元素最高价,与最低价态列举出来急用,全的 几种常见金属的最高价态与最低价态我是高一的,现在做氧化还原反应需要用, 求一篇《my favorite place in school》英语作文 作文 my favourite place at school 阿姆斯特朗是乘那个飞船登上月球的 How nice to hear from you again. Let me tell you something about the activity. I’m glad to have received your letter of Apr. 9th. I’m pleased to hear that you’re coming to China for a visit. I’m writing to thank you for your help during my st It’s so nice to hear from her again. , we last met more than thirty years ago.A. What’s more B. That’s to say C. In other words D. Believe it or not 你能发现金属元素的化合价与其原子结构的关系是：金属元素化合价的数值=_______?前面少了点 ,在化学反应中,金属元素一般是正化合价,如钠为+1价,镁为+2价,铝为+3价 Dear Dick,　　How nice to hear form you again.You want to know what is going on in schools in China?In short,things have begun to improve since schools were called on to reduce learning load.I don't know about others,but I used to have to work even so nice (it is) 还是 (is it) to hear from her?这种句式算倒装句么?应该是 it is 还是 is it? 什么是最低价态元素的化合物 什么是最高价态元素的化合物 英语作文：My favourite outdoor activity初三英语作文,知道的麻烦回答下,3Q!寒假作业= =!70字左右 究竟有没有显负化合价的金属元素?如果有,请列举一些,能写出这样的化合物是怎么制得的就更好了!如果没有,那是为什么?我感觉好象是存在的,比如第四主族的锗,第五主族的锑,第六主族的钋, Wang Bing is__(write)an e-mail to his English frind in the study用（）里所给的词的正确形式填空 he is going to write an e-mail to his friend tomorrow.(改为否定句) 螺栓、螺母等级中4.6级、5.8级、8.8级、10.用分别用材质制作? 求英语写话our rich and colourful school 必须包含下列要点：1.what kind of activies does your school often hold?2.what do you think of you school life?why? 在哪些化合物中金属元素显负化合价 某金属元素只有一种化合价,它与氯元素形成的化合价的相对分子质量比它与氧元素形成的化合价的相对分子质量比它与氧元素形成的化合价的相对分子质量大55,则该金属元素的化合价为（ 某金属元素只有一种化合价,已知它的化合物的相对分子质量为M,它的氢氧化物的相对分子质量为N ,则该金属的化合价为 （ 光盘行动英语作文内容包括：1你对光盘行动的看法 2在生活中你看到了那些不节俭的行为 3列举两件在生活中所做的有关节俭的事 4号召大家参与到节俭的生活中来 英语作文,响应光盘行动的, 以光盘行动为题的英语作文 有首英文歌 高潮歌词好像是baby don't say还有什么baby just say.有谁知道哈 小家碧玉意思是什么?