A student heated a mixture of iron filings and sulfur strongly. He saw a red glow spread through the mixture as the reaction continued. At the end of the experiment a black solid had been formed. a) Explain what the red glow indicates.

b) Give the chemical name of the black solid.

c) Write a word equation that and a balanced chemical equation to represent the reaction which has taken place.

d) The black solid is a compound. Explain the difference between the mixture of sulfur and iron and the compound formed by the chemical reaction between them.

Please answer part a, b, c, and d.
If you don't know the answer to all parts but you know the answer to one part then please answer it will still help