The average atomic mass of naturally occurring rubidium is 85.468 amu. The two isotopes of naturally occurring rubidium are rubidium-85 which is 72.2% abundant
and rubidium-87 which is 27.8% abundant. A 20.56 g sample of a natural rubidium
sample contains a mixture of both isotopes. How many of the atoms in the mixture
are rubidium-85?

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.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.