用NA表示阿佛加德罗常数，下列说法中正确的是
A．1mol甲烷的质量与NA个甲烷分子的质量之和相等
B．28g氮气与40g氩气所含的原子数目相等，都是NA个
C．2.3g钠由原子变成离子，失去的电子数为0.1NA
D．18g重水（D2O）所含的电子数为10NA
AC
根据摩尔的定义，每摩尔物质含有阿伏加德罗常数（NA）个微粒，所以A组答案是正确的，氮气是双原子分子，而氩气是单原子分子，28g氮气所含有的原子数为2NA个，40g氩气所含的原子数目是NA个；一个钠由原子变成离子时，将会失去1个电子，2.3g钠为0.1mol，由原子变成离子时失去的电子数为0.1NA；18g重水（D2O）所含的分子为0.9mol，而每个分子所含的电子数为10个，所以18g重水（D2O）所含的电子数为9NA；故答案为AC
There was a blacksmith(铁匠) who wasn't satisfied with his work. Once he complained, “I am not well and my work is too warm. I want to be a ____小题1:____ on the mountain. There it must be _____小题2:____, for the wind blows and the trees give a shade..” A wise man who had ___小题3:____ over all things replied, “Go you, be a stone.” And he was a stone, high up on the ____小题4:____ side. It happened that a stone-cutter ____小题5:____ that way for a stone and when he saw the one that had been the ____小题6:____, he knew that it was what he ____小题7:_____ and he began to cut it. The stone ____小题8:____ out, “This hurts! I no longer want to be a stone. A stone-cutter I want to be. That ____小题9:____ be pleasant.” The wise man, humoring him, said, “Be a cutter.” ____小题10:____ he became a stone-cutter and as he went seeking a suitable stone, he ____小题11:____ tired and his feet were sore（酸痛）. He ____小题12:____,” I no longer want to cut stone. I would be the sun; that would be pleasant.” The wise man ___小题13:___, “Be the sun.” And he was the sun. But the sun was warmer than the blacksmith, than a stone, than a stone-cutter, and he complained, “I do not ____小题14:___ this. I would be the moon. It ___小题15:____ cool.” The wise man spoke yet again, “Be the moon.” And he was the moon. This is warmer than being the sun,” ____小题16:___ he, “for the light from the sun ____小题17:____on me ever. I do not want to be the moon. I would be a ___小题18:____ again. That, indeed, is the ___小题19:____ life.” But the wise man replied, “I am ____小题20:___of your changing. You wanted to be the moon; the moon you are and you will remain.”
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