Which of these is considered a native element?
a. pyrite
b. galena
c. platinum
d. cinnabar

c. platinum

Explanation:

The native elements are elements that happend and synthethise naturally in nature, they basically happen and exist in pure form in nature and are divided into metals, semimetals and non metals, among this native elements we can find:

Metals

Platinum

Gold

Silver

Non metals

Sulfur and carbon

semimetals:

Bismuth and arsenic

a force of 500                  

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.