CT chung: \(\text{K}_{\text{x}}\text{O}_{\text{y}}\)
`@` Theo qui tắc hóa trị: \(\text{I}\cdot\text{x}=\text{II}\cdot\text{y}\rightarrow\dfrac{\text{x}}{\text{y}}=\dfrac{\text{II}}{\text{I}}\text{ }\)
`->`\(\text{x = 2, y = 1}\)
`->`\(\text{CTHH: K}_2\text{O}\)