A group two element `M` forms a carbide which is actually a methanide (i.e., it gives off methane of hydrolysis). Then, which of the following statements is/are correct for the element?

Options

A. The aqua complex of `M^(2+)` acidic.
B. Dolomite is an important mineral of the element M.
C. `M` is toxic.
D. `M(OH)_(@)` is amphoteric and dissolves in excess `NaOH` to form hexahydroxido complex.

Answer

A, D

Explanation

Be ( like Al) is the only element of group two which forms methanide, other group two elements from ethynide and allylide.
`Be_(2)C+H_(2)OtoBe(OH)_(2)+CH_(4)`
Aqua complex of `Be^(2+)` is acidic due to hydrolysis. Be (like Ba) is toxic,its hydroxide is amphoteric, but it forms only tetrahydroxido complex. Dolomite is `CaCO_(3).MgCO_(3)`