The enzyme that links RNA nucleotides together to form an RNA molecule is called RNA polymerase.

Here's a breakdown:

* RNA polymerase is a complex enzyme responsible for transcribing DNA into RNA.

* It uses a DNA template strand as a guide to build a complementary RNA molecule.

* During transcription, RNA polymerase adds RNA nucleotides one by one to the growing RNA chain.

* It uses the base pairing rules (A with U, C with G) to ensure the RNA sequence is a faithful copy of the DNA template.

Let me know if you'd like more information about the process of transcription!