题目

It is common for us to have some drink or some cakes at a cafe or a bookstore somewhere in a shopping center . But what about running a school cafe all by ourselves? That’s an unusual idea, and as a group of Senior 2 students put it, it was difficult but fun and exciting.Deluxe X Coffee is on the first floor of a school building at a middle school in Guangzhou. It was opened on April 5th this year. Unlike most cafes, Deluxe X Coffee only opens for three periods every day: from 12:25 to 13:00, from 17:55 to 18:35 and from 21:55 to 22:25. This is convenient so it is very popular among teachers23、右图是1一18号元素原子最外层电子数与原子核电荷数的关系图．试回答：（1）．我国“嫦娥工程”探月计划的一个重要目标是开发月球新能源--“氦-3”，已知10吨氦-3就能满足我国一年所有的能源需求．氦的相对原子质量为3，则氦原子核内有1个中子；（2）．钠原子核内有11个质子，它的原子核外有11个电子，在化学反应中易失（填“得”或“失”）电子，写出钠元素与硫元素所组成的化合物的化学式Na2S．（3）．在一个化学反应中，如果有元素化合价升高，同时就有元素的化合价降低．已知铝能与NaOH的水溶液反应生成NaAlO2和一种气体单质，从化合价的角度分析此气体单质的名称是：氢气．