Chemical reactions involve the breaking and forming of chemical bonds. Option A
A chemical reaction is the transformation of one or more chemicals (called reactants) into new compounds (called products). Atomic chemical bonds are broken and then reformed during this transition.
Since Option A correctly captures the essential characteristics of chemical reactions, it is the right choice. Choices B and C are not true; chemical reactions follow the conservation of mass and are not restricted to physical changes.
Missing parts;
Which of these is true about a chemical reaction is true?
A. Chemical reactions involve the breaking and forming of chemical bonds.
B. Chemical reactions only involve physical changes.
C. Chemical reactions violate the conservation of mass.
D. Chemical reactions are reversible processes.