The mass ratio of metal to oxygen in the oxide of a divalent metal is 5:2. The relative atomic mass of the metal is () A. 24B. 65C. 40D. 64

The mass ratio of metal to oxygen in the oxide of a divalent metal is 5:2. The relative atomic mass of the metal is () A. 24B. 65C. 40D. 64

According to the meaning of the title, the metal shows a + 2 valence and the oxygen shows a - 2 valence, and the chemical formula of the metal oxide is mo. suppose the relative atomic mass X of the metal is 5:2, then x: 16 = 5:2, x = 40

In the oxide of a trivalent metal, if the mass ratio of metal to oxygen is 7:3, the relative atomic mass of the metal is ()
A. 56B. 112C. 160D. 28

Let the element symbol of the metal be m, the metal element show + 3 valence, and the oxygen show - 2 valence. The chemical formula of the oxide is M2O3. The mass ratio of metal element to oxygen in the oxide is 7:3. Let the relative atomic mass of the metal be x, then 2x: (16 × 3) = 7:3, then x = 56