The synthesis of the iron(II) sulfide


What is the initial heating for?

It is used to start the reaction. They say it provides the activation energy (comparable to the energy which a child must provide to mount to a toboggan).

Then the reaction generates heat. How do you call such a reaction?

This is an exothermic reaction (the child slides on the toboggan!)

Two elementary substances combine to form a compound. What is the type of this reaction?

It's a synthesis reaction

Write the equation for the reaction!

$8Fe$ $ +$ $ S_8$ $\longrightarrow$ $ 8FeS$.