①沸点:HF>HCl>HBr>HI
②离子还原性:S2﹣>Cl﹣>Br﹣>I﹣
③酸性:HClO4>HBrO4>HIO4
④金属性:K>Na>Mg>Al
⑤气态氢化物稳定性:HF>HCl>H2S
⑥半径:O2﹣>F﹣>Na+>Mg2+ .