题干

如图所示,在电解水的实验中,通电一段时间后,若A试管中收集到了10mL的气体,则B试管中应同时收集到____ mL的气体.

①A试管中产生的气体是____,B试管中产生的气体是____,由此证明电解水时发生了____变化,该变化的文字表达式为____,基本反应类型是____.

②已知化学变化前后元素种类不变,那么由此实验可得出水是由____组成的.

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5,\u6c22\u6c14\uff08H2\uff09,\u6c27\u6c14\uff08O2\uff09,\u5316\u5b66,\u6c34 \u2192\u901a\u7535

同类题3

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Only a Ribbon

    In one of the London hospitals,a short time ago,there was a young doctor. He noticed one of the patients,a ten-year-old poor girl called Katie,who had a very painful illness.

    Katie lay in her bed,day after day,with nothing to help her forget her pain and cheer up. One day the doctor noticed her trying to make a doll of her finger, and speaking to it. But she was soon tired of it,and lay back into her bed.

    That afternoon,the young doctor saw a beautiful ribbon in a shop window. He thought that it might help cheer the little girl up,so he went in and bought it for her. When he handed the ribbon to the girl,she was too surprised to speak. There were tears in her eyes. This little gift made her feel rich and happy.

    The nurse later told the doctor that the girl played with the ribbon all day long. She twisted(盘绕)it round her head. She held it in her hand while she slept.

    Some weeks later,Katie's illness became worse,and it was necessary to perform a dangerous operation. When Katie was brought into the operation mom,she cried out for the young doctor. He was brought,and he held one of the girl's hands,while the other tightly held the ribbon.

    During the operation,the ribbon fell off Katie's hand. As soon as she woke up and opened her eyes,she looked at her friend and said in a low voice,“My ribbon.”The doctor gave it to her and she smiled happily.

    It was only a little gift,but it made the girl's stay in the hospital bright with beauty and love.