Asteroids are relatively small to large chunks of celestial body that have dark surface. other asteroids are thought to be rocky and to have a core made of A. Iron or cobalt
B. Cobalt or Nickel
C. Nickel or Zinc
D. Iron or Nickel

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

it is a good conductor

explanation:

the answer to this question is 3.

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.