Final answer:
The law of conservation of matter, also known as the law of conservation of mass, states that hazardous substances like mercury, lead, or cadmium cannot simply disappear. Instead, their amount stays constant in a closed system. (option c is the correct answer)
Step-by-step explanation:
The Law of Conservation of Mass states that in a closed system, the mass of substances before a chemical reaction is equal to the mass of the products after the reaction. In the context of e-waste in landfills, hazardous substances like mercury, lead, or cadmium are present in electronic devices. When these devices are disposed of in landfills, these substances do not disappear but can instead leach into the soil and water, posing environmental and health risks.
For example, when a cell phone containing hazardous materials decomposes, the Law of Conservation of Mass implies that the total mass of the substances involved remains constant, even if their form or location changes. This emphasizes the need for proper e-waste management to mitigate the impact of hazardous substances on the environment.