Understanding the Oxides
In the given scenario, element X forms two oxides, Xo and Xo2, with different proportions of oxygen. The percentages of oxygen in these compounds indicate how oxygen combines with the element.

Oxides Composition
- **Xo**: Contains 50% oxygen.
- **Xo2**: Contains 60% oxygen.
This implies that in Xo, 50% of its mass is oxygen, while in Xo2, 60% of its mass is oxygen.

Mass Calculation
To understand how oxygen combines with the element, we can calculate the mass of oxygen that combines with 1g of element X:
- For **Xo**:
- If Xo contains 50% oxygen, then:
- Mass of oxygen = 0.5 g (from 1 g of Xo)
- For **Xo2**:
- If Xo2 contains 60% oxygen, then:
- Mass of oxygen = 0.6 g (from 1 g of Xo2)

Ratio of Masses of Oxygen
The question states that the ratio of the masses of oxygen combining with 1g of element X in both oxides is 2:3.
- From our calculations:
- Mass of oxygen in Xo = 0.5 g
- Mass of oxygen in Xo2 = 0.6 g
To express the masses in a ratio format:
- Convert 0.5 g and 0.6 g into a common format:
- 0.5 g = 5 parts
- 0.6 g = 6 parts
Thus, the ratio is:
- **5:6**, which can be simplified to **2:3** when expressed in lowest terms.

Conclusion
The ratio of the masses of oxygen combining with 1g of element X in the oxides Xo and Xo2 indeed reflects the stated 2:3 ratio, confirming the stoichiometry and chemical behavior of the element in forming different oxides.