Name three features or structures commonly found in the environment surrounding a black hole.

Accretion disk, corona, jets, dusty torus

Which type of electromagnetic radiation is primarily used to study the corona of a black hole, and why?

X-rays, because the corona is a superheated plasma of loose electrons that emits a lot of X-rays.

I can describe the extreme environment of black holes and how humans study them.

1
The environments around black holes include a corona of hot electrons, a bright accretion disk of gas and dust, and sometimes jets that span millions of lightyears.
2
Scientists categorize black holes into four types: primordial, intermediate mass, stellar mass, and supermassive.
3
An active galactic nucleus (AGN) can have several different structures, including the accretion disc, corona, and a dusty torus.