Question

Energy that enters or leaves a system during a chemical reaction comes from:

a) the building and breaking of chemical bonds.
b) the conversion of mass to energy.
c) heat absorbed from the surroundings.
d) the kinetic energy of electron motion.

Answer 1

The energy that enters or leaves a system during a chemical reaction comes from the building and breaking of chemical bonds.

Step-by-step explanation:

Chemical reactions involve the breaking and forming of chemical bonds. The energy that enters or leaves a system during a chemical reaction comes from the building and breaking of these chemical bonds. When new bonds are formed that are stronger than the broken bonds, energy is released. On the other hand, if the new bonds are weaker than the broken bonds, energy needs to be added to the reaction.