The shift of equilibrium in response to a change in conditions is based on the principle established by which scientist?

The correct answer is attributed to Le Chatelier, who formulated a principle that explains how a system at equilibrium reacts to changes in concentration, temperature, or pressure. According to Le Chatelier's principle, when an equilibrium system experiences a change in applied conditions, it will shift in such a way as to counteract the change and re-establish equilibrium.

For instance, if the concentration of a reactant is increased in a reversible reaction, the equilibrium will shift toward the products to reduce the concentration of the reactant, thereby helping the system restore its balance. This principle is fundamental in predicting the behavior of chemical reactions and is widely applicable in various chemical and industrial processes.

In contrast, the other scientists mentioned established important laws in their respective areas—Charles is known for his gas law relating volume and temperature, Boyle focused on the relationship between pressure and volume of gases, and Dalton is recognized for his atomic theory and the law of partial pressures. While their contributions are significant in the field of chemistry, they do not relate to the concept of equilibrium shifts in response to external changes.