You are working in your laboratory and decide to do some cleaning. you find a test tube with some brown substance congealed at the bottom. you take a piece of iron wool to scrub it out, but cannot remove it. you leave the iron wool in the test tube and set it aside to clean your beakers instead. you do not realize the test tube is next to the heater and after a few minutes, a brown gas starts smoking out of the test tube, followed by a reddish-brown gas. upon observation, the iron wool is coated in a yellow-brown substance. you realize that the mystery substance was
a. bromine (br) b. iodide (i) c. argon (ar) d. scandium (sc)