It says in the Encyclopaedia Britannica that the Bermejo River is a western tributary of the Paraguay River in south-central South America. This is probably true because the Encyclopaedia Britannica is a highly reliable reference source.
【简答题】硼是第ⅢA族的元素,自然界中有许多硼化合物,如: 硼镁矿 硼砂 硼酸 偏硼酸钠 Mg 2 B 2 O 5 ?H 2 O Na 2 B 4 O 7 ?10H 2 O H 3 BO 3 NaBO 2 请回答下列问题: (1)上述所列硼化合物中,硼的质量分数最高的是:______; (2)工业上以硼镁矿为原料制取硼.该工艺的中间过程会发生反应:B 2 O 3 +3Mg=2B+3MgO,反应的氧化剂是:_...