Question

Why carbon can form stable $C=C$ bond where as silicon can't form $Si=Si$ ?

• A. Poor overlap of $p\pi -d\pi$ in silicon
• B. Poor overlap of $p-s$ in silicon
• C. Poor overlap of $p\pi -s$ in silicon
• D. Silicon do not have vacant orbital

Answer 1

Answer: (A)

Poor overlap of $p\pi -d\pi$ in silicon

Silicon can't form $Si=Si$ due to poor overlapping of $p\pi -d\pi$ bond. Si has no tendency to form double bonds with itself due to its large size. The bond formation is difficult du to the large size.