How does the potential-energy diagram for a reaction indicate whether the reaction is endothermic or exothermic? an endothermic reaction has reactants that are lower in energy than products because energy is absorbed to form the products. an endothermic reaction has reactants that are higher in energy than products because energy is released to form the products. an exothermic reaction has reactants that are lower in energy than products because energy is released to form the products. an exothermic reaction has reactants that are higher in energy than products because energy is absorbed to form the products.

The right answer is A.

An endothermic reaction is a transformation that absorbs energy. Indeed, it needs this energy input to break the bonds that exist in the reagents (which are stronger than in the products).

An exothermic reaction is a transformation that releases energy. Indeed, the bonds that exist in the reagents are weaker than those present in the products. Thus, a surplus of energy is released.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times