X元素原子的质量数为m,核内中子数为n,则Wg X 2+ 离子含有的电子的物质的量约为

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='21382' and id < 1854739 and id<>'1854739' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='21382' and id > 1854739 and id<>'1854739' order by id asc limit 5