【单选题】设N A 为阿伏加德罗常数,下列叙述正确的是( ) ① 7 Li + 中含有的中子数与电子数之比为2:1 ②Cl 2 的摩尔质量与N A 个Cl 2 分子的质量在数值和单位上都相等 ③常温下,11.2L的甲烷气体中含有的氢、碳原子数之比为4:1 ④活泼金属从盐酸中置换出1molH 2 ,转移电子数为N A ⑤在C 2 H 6 分子中极性共价键与非极性共价键数之比为3:1 ⑥500mL0.5mo...
【简答题】Why did Erin go to Ed Masry’s office? 2. Did Erin succeed in claiming for compensation in court? 3. Why did Erin ordered just a cup of coffee for herself at the restaurant? 4. Why did Erin collect new...