Question

What is unique about carbon?

Answer 1

Its ability to `"catenate................."`, that is to form `C-C` chains.

Explanation:

See this [old answer.](https://socratic.org/questions/why-is-carbon-important-for-forming-complicated-molecules?source=search)

Equivalent chemistry based on `"silicon"` is much more unlikely due to unfavourable thermodynamic and kinetic properties.