题目

(10分)完成下列反应的文字表达式，并回答有关问题。(1)水通电分解：                       ，在反应前后没有改变的微粒为          (2)实验室用双氧水制取氧气(二氧化锰粉末作催化剂)：                            ，基本反应类型是            。(3)碳酸氢铵加热分解：                                ，保持该化肥应注意          (4)镁条燃烧：                                ，10. —Has Jack finished his homework yet?—I don't know,but he (do) it the whole afternoon.