cho A g hỗn hợp bột nhôm sắt vào sắt dd NaOH dư thấy còn lại 2,8g chất rắn không tan. Nếu cho hỗn hợp vào dd H2So4 dư thấy thoát ra 4,48g lít khí đktc và thu đc dung dịch X xác định giá trị a tìm khối lượng muối có trong X

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.