Answer: \(Fe(OH)_2\)
Explanation:
The chemical formula involves ferrous ions \(Fe^{2+}\) and hydroxide ions \(OH^-\). They combine in 1:2 ratio so as to form a neutral and stable compound.
\(Fe^{2+}+2OH^-\rightarrow Fe(OH)_2\)
The chemical formula is written by exchange of valencies as shown in the image attached.