A.氮化硅中Si、N两种元素的质量比为4:3 |
B.氮化硅中氮元素的质量分数为60% |
C.14g氮化硅中含硅8.4g |
D.氮化硅的相对分子质量为l44 |
A.10% | B.25% | C.30% | D.35% |
A.3% | B.2% | C.1% | D.0.2% |
A.50% | B.60% | C.65% | D.70% |
A.苯酚的相对分子质量为50 |
B.苯酚由碳、氢、氧三种元素组成 |
C.苯酚中碳、氢、氧三种元素的质量比为36:3:8 |
D.每个苯酚分子中含有13个原子 |
A.0.71% | B.1.42% | C.2.18% | D.3.61% |
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