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元素周期表中--------元素种类最多 为什么23克金属钠变为钠离子时,失去的电子数为NA如题,通俗点说..为什么失去1MOL电子,为什么变成NA+就是一MOL? 《钢铁是怎样炼成的》读书笔记,要求500字, 小学读书笔记急用!200字左右,不要长! 五年级读书笔记200字—300字给点200字—300字的读书笔记吧!下跪中. 五年级读书笔记400字 含铁物质指、、、 世界上含有铁的物质有多少种? Na离子,失去多少电子 关于压力测检及仪器的一道题用弹簧管压力表测量蒸汽管道内压力,仪表低于管道安装,两者所处标高为1.6m和6m.若仪器指示值为0.7mpa,试求蒸汽管道内的实际压力值.已知 蒸汽凝结水的密度 为966 具有相同核电荷数的微粒一定属于同一种元素吗?具有相同核电荷数的微粒为什么不可以说一定属于同一种元素?比如说CL-离子和CL原子就不可说是同一种元素是是吗?为什么?是因为他们不属于 什么青菜含铁多 I can recognize the characters that she writes. 什么蔬菜含铁多, 1.it was not until she look off her dark glasses that i ___(recognize)the she was a famous film star.2.the doctor said,"why not ___(try,take)exercise to lose weight?3.Charles Cabbage is generally considered ___(invent)the first computer4.___(determin 下雨天鱼好钓还是晴天鱼好钓 蔬菜含铁多的是哪一种? 下雨天能钓到鱼吗? 下雨天能不能钓到鱼 请问：下雨天,能钓到鱼吗? 下雨天怎么才能钓到鱼呀 有首歌求歌名,第一句是if i can reach the star ,还有一句i can change the star If could reach the stars I'd pull one down for you shine.这是什么意思阿?一句英语、但我不懂它得意思! reach for the Aim high,reach for the star 对括号部分提问 1 Those are (watermelons) 2 She will visit (that)woman 3 They often go there with(their)books 4 (The men)play chess once a week 5 (Mine) is better She is( ) at the news that her friends will come to visit herShe is s ________ at the news that her friends will come to visit her 岩层断开并显著位移在断开面以上叫上盘,以下叫下盘,上盘上升下盘下降叫正断层上盘下降下盘上升叫逆断层这句话对吗 “Mary,what about going boating if it ___________ tomorrow?” “Good idea!”A.not rain B.will rain C.doesn’t rain D.won’t rain为什么选C? What about going swimming together?That sounds ____ a good idea介词填空 ( )what's that woman?----she's_____.A.MIss Li B.a teacher C.over there 这封英文信这是我的英文信里的一小段内容,I also want to express my sympathies for your divorce It troubles me to see marriages fail.My friends always preach to not get married because it would be the death of the relationship.But I t