a) ta có CTHH: \(Mg^{II}_x\left(RO\right)^{II}_y\)
\(\rightarrow II.x=II.y\rightarrow\dfrac{x}{y}==\dfrac{II}{II}=\dfrac{1}{1}\rightarrow\left\{{}\begin{matrix}x=1\\y=1\end{matrix}\right.\)
\(\rightarrow CTHH:MgRO\)
b) biết \(PTK_{O_2}=2.16=32\left(đvC\right)\)
\(PTK_A=3,25.32=104\left(đvC\right)\)