1.镁在空气中燃烧：_____Mg +___ O2 ==_____MgO 2.铁在氧气中燃烧：______Fe +____O2 ==_____ Fe3O4 3.铜在空气中受热：_____Cu + ____O2 ==______CuO 4.铝在氧气中燃烧：______Al + ______O2 ====_______Al2O3 5.氢...