The correct option is **D. Einstein**. ### Explanation of the Correct Answer Albert Einstein is the scientist who famously stated that matter can be converted into energy, encapsulated in his groundbreaking equation \(E=mc^2\). This equation expresses the equivalence of mass (m) and energy (E), with \(c\) representing the speed of light in a vacuum (approximately \(3 \times 10^8\) meters per second). 1. **Understanding the Equation**: - **E** stands for energy. - **m** stands for mass. - **c** is the speed of light, which is a very large number. This means that even a small amount of mass can be converted into a large amount of energy. - The equation implies that mass and energy are interchangeable; they are different forms of the same thing. 2. **Historical Context**: - Einstein published his theory of relativity in 1905, which fundamentally changed our understanding of physics. The idea that mass can be converted into energy was revolutionary and laid the groundwork for nuclear physics and the development of nuclear energy. 3. **Applications**: - This principle is the basis for nuclear reactions, such as those that occur in the sun and in nuclear power plants. In these processes, a small amount of mass is converted into a significant amount of energy, demonstrating the practical implications of Einstein's theory. ### Why the Other Options Are Incorrect - **A. Boyle**: Robert Boyle is known for Boyle's Law, which describes the relationship between the pressure and volume of a gas at constant temperature. He did not contribute to the concept of mass-energy equivalence. - **B. Lavoisier**: Antoine Lavoisier is often referred to as the "father of modern chemistry." He is known for his work on the law of conservation of mass and for naming oxygen and hydrogen. While he made significant contributions to chemistry, he did not address the conversion of matter into energy. - **C. Avogadro**: Amedeo Avogadro is best known for Avogadro's Law, which states that equal volumes of gases, at the same temperature and pressure, contain an equal number of molecules. His work focused on molecular theory and gas behavior, not on the conversion of matter to energy. ### Summary of Key Points - **Einstein's Equation**: \(E=mc^2\) shows the equivalence of mass and energy. - **Revolutionary Impact**: This concept transformed our understanding of physics and led to advancements in nuclear energy. - **Historical Figures**: Boyle, Lavoisier, and Avogadro made significant contributions to chemistry but did not address the matter-energy relationship. ### Revision Summary - Albert Einstein formulated the equation \(E=mc^2\), establishing the principle that matter can be converted into energy. - This principle is foundational in nuclear physics and has practical applications in energy production. - Other scientists like Boyle, Lavoisier, and Avogadro contributed to chemistry but did not address the mass-energy equivalence.