Final answer:
The chief port city on the Amazon River, where the Rio Negro empties into the Amazon, is Manaus
Step-by-step explanation:
The chief port city on the Amazon River, where the Rio Negro empties into the Amazon, is Manaus. Manaus is an ideal core city for economic trade due to its location and access to the river and ocean. The city has a free-trade zone and an industrial complex for the production of electronic goods.