【单选题】What was the one thing Bill said he enjoyed?
【简答题】Mr, Evans lives and works in Sydney. Last week he had a holiday, but he didn’t know to go. He said to his friend Robert,” I hate the hot weather here, but I can’t a cool place in Australia. Where shou...
【多选题】短周期元素中,A元素原子最外层电子数是次外层电子数的2倍;B元素最外层电子数是其内层电子总数3倍;C元素原子次外层电子数等于其原子核外电子总数的一半;D元素原子最外层有1个电子,D的阳离子与B的阴离子电子层结构 相同,则4种元素原子序数关系中正确的是( )
【简答题】在短周期元素中:原子核外电子总数是其最外层电子数 2 倍的元素是 ________ ,原子电子层数和核外最外层电子数相等的元素是 ________ ,最外层电子数为电子层 2 倍的元素是 ________ .
【单选题】短周期元素X、Y、Z三种原子核外电子总数为32,都可形成常温下气体单质。X原子最外层电子数是其内层电子数的3倍;Y的气态氢化物与其最高价氧化物对应的水化物恰好反应的产物只有一种A,A的水溶液显酸性。下列说法正确的是
B.
X元素形成的单质其摩尔质量一定是32g·moL - 1
【简答题】Bob went to Beijing during the Spring Festival. He ( ) come back from Beijing. He went there ( ) and enjoyed the beautiful ( ) on the way. He found that Beijing's ( )...