The chemical formula of mineral beryl
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → $(Be_3Al_2Si_6O_{18})$.
Beryl is a naturally occurring mineral and an important source of beryllium. It is composed of beryllium, aluminum, silicon, and oxygen.
The correct formula, Be₃Al₂Si₆O₁₈, represents the structure of beryl, which consists of rings of silicate (Si₆O₁₈) groups connected by beryllium (Be²⁺) and aluminum (Al³⁺) ions.
The other options provided are complex compounds or coordination compounds, which are unrelated to the naturally occurring mineral beryl.
Summary:
The chemical formula of beryl is Be₃Al₂Si₆O₁₈.