Question

what is the main goal of the investigation as described in the document? to test the durability of lab equipment to identify unknown metals using flame tests to create new chemical solutions to measure the temperature of flames

Explanation:

The question asks for the main goal of an investigation described in a document, but the document's content isn't provided, so an answer cannot be given.

Answer:

There is no information in the question - body about which document is referred to. Without the content of the document, it's impossible to determine the main goal of the investigation.