初三“化学用语”过关练习提纲1、写出下列各化学用语的表达意义:O____________________________________ Ag_____________________________________2O_______________________________ O2_________________________________________2SO2_____________________________ 2O2________________________________________CO ________________________________________ Mg2+_____________________________3SO42--_______________________________ nCO3_________________________________ 2 写出下列化学符号中“2”的意义: 2Pt Cl2____________________________________________2OH-- 2S2—_________________________________________2CO2 2SO42--_____________________________________3 用对应的化学符号表达下列各化学述语:两个金原子____________ ,两个过氧化氢分子 __________ ,两个硝酸根离子__________ ,正三价的铁元素____________ ,亚铁离子________ ,四个氧化铝分子_____________ ,正一价的铵根 ___________ ,四氧化三铁 ___________ , 氧化铁_________ , 氧化亚铁_________________,大