What are the key principles of green chemistry?

The key principles of green chemistry focus on designing chemical processes and products that minimize the use and generation of hazardous substances. Waste reduction is a fundamental principle, as it emphasizes the importance of designing processes that either produce less waste or utilize waste in a way that it can be transformed into useful products. Energy efficiency is another core aspect, targeting the reduction of energy consumption in chemical processes, which not only lowers costs but also reduces the environmental impact associated with energy production. Lastly, the use of renewable feedstocks is crucial because it encourages the use of raw materials that are sustainable and can be replenished, thereby reducing dependency on depleting fossil resources.

In contrast, the other options deviated from these principles. The use of non-toxic materials paired with waste generation contradicts the goal of green chemistry, which aims to minimize waste. Maximizing product yield and energy consumption does not align with the principles of green chemistry, as it ignores the need for energy efficiency. Lastly, the promotion of synthetic chemicals only runs counter to the aim of incorporating renewable resources and safer alternatives into chemical practices. These considerations make the focus on waste reduction, energy efficiency, and renewable feedstocks the correct choice for the key principles of green chemistry.