Question

select the independent clause. after a lightning bolt passes through the air, the compression and subsequent rapid expansion of the air molecules produces the booming sound of thunder.

Explanation:

An independent clause can stand alone as a complete sentence. In the given sentence, "the compression and subsequent rapid expansion of the air molecules produces the booming sound of thunder" can stand alone and express a complete thought. The clause "After a lightning - bolt passes through the air" is a dependent clause as it starts with a subordinating conjunction "After" and cannot stand alone.

Answer:

the compression and subsequent rapid expansion of the air molecules produces the booming sound of thunder