Nanoparticles are small collections of atoms that can have properties and behaviors that are very different from a bulk sample of the material. Gold and silver are two metals that are able to form nanoparticles with useful properties. One difficulty in the manufactured formation of these particles is avoiding methods that involve toxic chemicals. One potential method for producing gold nanoparticles is to use light energy to reduce gold ions, A u 3 + , to neutral gold metal, A u . The difficulty with this method lies in finding a system that can efficiently capture light energy and convert it into chemical energy. Researchers tested the ability of chloroplasts extracted from two different plant species, one an aquatic pond weed and the other spinach, to use light to create gold nanoparticles.

Question

In a second study, the researchers took spinach extract and varied the concentration of the gold ions in the solution. The solutions were then either exposed to light or kept in the dark for 30 minutes at 24 ∘ C . The data is presented in Figure 2.

In a third study, the researchers used spinach extract with 2 mM gold ions and exposed the solutions to varying intensities of light for varying time intervals at 24 ∘ C . The data is presented in Figure 3.

Which of the following is the BEST explanation for the experimental setup in Study 2?

Answer 1

In Study 2, the researchers aimed to investigate how different concentrations of gold ions in the solution affect the formation of gold nanoparticles when exposed to light compared to keeping the solutions in the dark. The best explanation for this experimental setup is that it allows for the examination of the relationship between the concentration of gold ions and the effect of light on the reduction process. By contrasting the results from light exposure to those kept in the dark, the researchers can assess whether light significantly enhances the creation of gold nanoparticles and how it interacts with varying concentrations of gold ions. This setup helps to elucidate the efficiency and mechanism of the light-induced reduction process facilitated by the spinach extract, potentially revealing critical information about optimizing nanoparticle synthesis without toxic chemicals.