... Mg2+, Al3+ Cõu Chn th t gim dn hot ng hoỏ hc ca cỏc kim loi kim A Na-K-Cs-Rb-Li B Cs-Rb-K-Na-Li C Li-Na-K-Rb-Cs D K-Li-Na-Rb-Cs Cõu Phỏt biu no di õy l ỳng A Kim loi kim cú nhit núng chy v nhit ... A Fe2+, SO4 2-, NO 3-, H+ B Fe2+, Fe3+, SO4 2-, NO 3-, H+ C Fe3+, SO4 2-, NO 3-, H+ D Fe2+, SO3 2-, NO 3-, H+ 17 Cho lung khớ H2 d i qua ng nghim cha hn hp Al2O3, CuO, MgO, FeO, Fe3O4 Gi thit cỏc phn ... cha ion Cl- v SO4 2- hoc c l nc cng tm thi D Nc cng cú cha ng thi anion HCO 3- v SO4 2- hoc Cl- l nc cng ton phn Cõu 21 Cú cỏc cht sau NaCl, NaOH, Na2CO3, HCl Cht cú th lm mm nc cng tm thi l A NaCl...