A:25℃时,pH=3的1.0 L NaHSO3溶液中,含Na+数目为0.001 NA
B:2.3 g甲苯和丙三醇的混合物中,含氢原子数目为0.2NA
C:标准状况下,2.24 L溴乙烷中含共价键数目为0.7 NA
D:5.6 g Fe投入100mL 3.5 mol/L硝酸中,充分反应,转移电子总数为0.3 NA
—How do you spend the coming May Day holiday?— I haven't decided. I wonder during the holiday.
如图,电源电压恒定,电阻R1=10Ω,R2=15Ω,R阻值一定但未知,当单刀双掷开关S掷向a(同时与b断开)时,电压表示数为2.0V,若掷向b(同时与a断开),电压表示数可能为( )
假如你跟随郑和下西洋,下面哪些地区是没有到达的( )