【简答题】下表为元素周期表的一部分,请参照元素①-⑧在表中的位置,用化学用语回答下列问题: (1)②、④、⑤的原子半径由大到小的顺序为____________________。 ②、④、⑤的离子半径由大到小的顺序为____________________。 (2)①②⑥⑦四种元素所对应的气态氢化物最稳定的是________,最不稳定的是_____(填化学式)。 (3)②、③可形成既含离子键又含共价键的化合物...
【简答题】短周期元素A、B、C、D、E的原子序数依次增大,其元素特征信息如表: (1)D原子结构示意图为 _______ ,A在周期表中的位置为 。 (2)B和C形成的化合物的电子式为 。 (3)B和D简单离子的半径大小为 。 (4)元素非金属性强弱比较有很多方法,其中B和E的非金属性强弱的研究方案中不可行的是 (填序号)。 a.比较两种单质的颜色 b.比较两种单质与H 2 化合的难易程度 c.依据两元素在...
【简答题】歌曲-填空Listen to a song and fill in the blanks with what you hear. 电影《音乐之声》插曲 Let’s start at the very beginning A very good place to start When you read you begin with a b c When you sing you begin with...
【简答题】短周期元素A、B、C、D、E的原子序数依次增大,其元素特征信息如下表 ①D原子结构示意图为____________;A在周期表中的位置为________________; ②用电子式表示B和C形成的化合物 ___________; ③B和D简单离子的半径大小为__________;(用离子符号和“>”、“=”或“④元素非金属性强弱比较有很多方法,其中B和E的非金属性强弱的研究方案中不可行的是___...
【简答题】Managers often have desks that are surprisingly empty! These empty desks can show that the manager often travels and is out of the office most of the time. An empty desk can also show how powerful the...
【单选题】Why may equity finance be preferred to debt finance for developing countries?
A.
A fall in domestic income automatically reduces the earnings of foreign shareholders without violating any loan agreement.
B.
There are laws insuring against any default with equity finance.
C.
The risk is shared between debtor and creditor with debt finance.
D.
The tax structure leaves equity finance unconstrained.
E.
Repayments are unaffected by falls in real income.
【单选题】按照塞尔的分类,“承诺”、“威胁”、“发誓”( )同一类言语行为
【简答题】听对话,回答问题。 1. What can you do in the Study Centre? A. Take exams. B. Talk with friends. C. Do language practice. 2. How many books can you borrow at a time? A. Six. B. Four. C. Two. 3. What's the speak...
【简答题】A~E是原子序数依次增大的五种短周期元素,其有关性质或结构信息如表所示: 元素 A B C D E 有关性质或结构信息 单质是空气中主要成分之一,其氢化物水溶液呈碱性 原子核外有两个未成对电子 日常生活中常见的金属,通常用电解法冶炼其单质 其简单阴离子带两个单位负电荷 单质有毒,常温下为有色气体,常用于自来水消毒 请结合表中信息完成下列各小题: (1)C在元素周期表中的位置是______,D的简单...
【单选题】To finance the national debt, the government issues a variety of debt securities. The most widely held liquid security is the Treasury bill, which is commonly issued by the ministry of finance. Howeve...