挑战习题
1/5单选题
难度:

1.计算硝酸铵(NH4NO3)中氮元素的质量分数。
A 34%
B 36%
C 35%
D 37%
提示1:
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提示2:
IOawruWFg+e0oOeahOi0qOmHj+WIhuaVsO+8mg0KPGltZyB3aWR0aD0zNzggaGVpZ2h0PTQ0IHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMTAvRDEvckJBQ0ZGTVM3WURReHpReUFBQUl0a3MyUnZzODg5LnBuZyI+
正确答案:Qw==
5YWI566X5Ye6Tkg8c3ViPjQ8L3N1Yj5OTzxzdWI+Mzwvc3ViPueahOebuOWvueWIhuWtkOi0qOmHj++8mjE077yLMcOXNO+8izE077yLMTbDlzPvvJ04MO+8jOWGjeiuoeeul+awruWFg+e0oOeahOi0qOmHj+WIhuaVsO+8miA8aW1nIHdpZHRoPTM3OCBoZWlnaHQ9NDQgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC8xMC9EMS9yQkFDRkZNUzdZRFF4elF5QUFBSXRrczJSdnM4ODkucG5nIj4=