Scientists have concluded that the uppermost part of the mantle is partially-molten. Which observation helped them reach this conclusion? Both P and S waves slow down when they reach this layer.

Both P and S waves speed up when they reach this layer.

P waves do not travel through this layer.

S waves do not travel through this layer.

Both P and S waves slow down when they reach this layer

Explanation:

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.