A、N<sub>1sub>=N<sub>2sub>=N<sub>3sub> B、N<sub>1sub>>N<sub>2sub>>N<sub>3sub> C、N<sub>2sub>>N<sub>1sub>>N<sub>3sub> D、N<sub>3sub> =N<sub>1sub>>N<sub>2sub>
A、N<sub>1sub>=N<sub>2sub>=N<sub>3sub> B、N<sub>1sub>>N<sub>2sub>>N<sub>3sub> C、N<sub>2sub>>N<sub>1sub>>N<sub>3sub> D、N<sub>3sub> =N<sub>1sub>>N<sub>2sub>
A、CO B、CO<sub>2sub> C、CH<sub>4sub> D、N<sub>2sub>
A、标准状况下,22.4LH<sub>2sub>O含有的分子数为NA B、常温常压下,1.06gNa<sub>2sub>CO<sub>3sub>含有的Na+离子数为0.02N<sub>Asub> C、通常状况下,N<sub>Asub>个CO<sub>2sub>分子占有的体积为22.4L D、物质的量浓度为1.5mollL的MgCl<sub>2sub>溶液中,含有Cl-数为3N<sub>Asub>
A、O<sub>2sub> B、CO<sub>2sub> C、Na+ D、N<sub>2sub> E、NaHCO<sub>3sub>
A、U<sub>1sub>/U<sub>2sub>=N<sub>1sub>/N<sub>2sub>      B、U<sub>1sub>/U<sub>2sub>=N<sub>2sub>/N<sub>1sub> C、N<sub>1sub>/N<sub>2sub>=I<sub>2sub>/I<sub>1sub>       D、N<sub>1sub>/N<sub>2sub>=I<sub>1sub>/I<sub>2sub>
A、H<sub>2sub>的辐射能力比N<sub>2sub>大得多 B、H<sub>2sub>比热系数N<sub>2sub>大得多 C、H<sub>2sub>比重比N<sub>2sub>小得多 D、H<sub>2sub>导热系数比N<sub>2sub>大得多
A、水蒸气分子量比O<sub>2sub>、N<sub>2sub>小 B、水蒸气分子的极性比O<sub>2sub>、N<sub>2sub>要大 C、水蒸气的凝聚温度比O<sub>2sub>、N<sub>2sub>高 D、水蒸气在空气中含量比O<sub>2sub>、N<sub>2sub>要少
A、n<sub>1sub>≈n<sub>2sub> B、n<sub>1sub>=n<sub>2sub> C、n<sub>1sub>>>n<sub>2sub> D、n<sub>1sub><<n<sub>2sub>
A、C<sub>nsub>H<sub>2n+2sub>O<sub>2sub> B、C<sub>nsub>H<sub>2nsub>O<sub>2sub> C、C<sub>nsub>H<sub>n+2sub>O<sub>2sub> D、C<sub>nsub>H<sub>2n+1sub>O<sub>2sub>
A、n<sub>1sub>=n<sub>2sub> B、n<sub>1sub>>n<sub>2sub> C、n<sub>1sub><n<sub>2sub> D、无法确定