Which statement is true about a reaction represented by a chemical equation that shows energy as a reactant? 
A.
It absorbs energy.

B.
It releases energy.

C.
It is a replacement reaction.

D.
It is a combustion reaction.

A. It absorbs energy.
reactants are located on the left side of the equation, meaning energy among with other reactants were needed to get the reaction going, so it absorbed energy, which is also the endothermic process. The opposite of that would be having energy on the right side with the products which means that the reaction would've released energy which is the exothermic process. Hope this helps!

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.