Final answer:
Option D) 2P4 + 3O2 → 2P2O3 does not demonstrate the conservation of matter.
Step-by-step explanation:
The chemical equation that does not demonstrate the conservation of matter is option D) 2P4 + 3O2 → 2P2O3. The number of atoms before and after the reaction is not equal, which means that matter is not conserved. In this equation, there are fewer oxygen atoms in the product than in the reactant, violating the conservation of matter principle. To balance the equation, you would need to multiply the product by 3, resulting in 4P4 + 3O2 → 6P2O3.