Which scientist laid the foundation of modern chemical science by establishing two important laws of chemical combination?

Introduction / Context:
This question belongs to the history of chemistry and focuses on the early development of laws of chemical combination. Understanding which scientist first formulated key quantitative laws, such as the law of conservation of mass, helps you see how modern chemistry moved from qualitative observations to quantitative science. Antoine L. Lavoisier is often called the father of modern chemistry because of his pioneering work in this area.

Given Data / Assumptions:

• The question asks about a scientist who laid the foundation of chemical sciences.
• Clue: he established two important laws of chemical combination.
• Options include Proust, Lavoisier, Rutherford, Democritus and Dalton.
• We assume standard school syllabus coverage of these scientists.

Concept / Approach:
The central idea is to recall which chemist is associated with quantitative laws regarding how substances react and combine. Lavoisier carried out careful experiments on combustion and chemical reactions. He formulated the law of conservation of mass and contributed significantly to the understanding of elements and compounds. Proust is known mainly for the law of definite proportions. Dalton is known for atomic theory and the law of multiple proportions. Rutherford is associated with the nuclear model of the atom. Democritus proposed a philosophical idea of indivisible atoms but not quantitative laws.

Step-by-Step Solution:
Step 1: Recall that Antoine L. Lavoisier performed accurate mass measurements during chemical reactions. Step 2: From these experiments he formulated the law of conservation of mass, which states that mass is neither created nor destroyed in a chemical reaction. Step 3: Lavoisier also helped clarify the concept of elements and compounds, and laid groundwork for later laws of combination, providing a quantitative basis for chemistry. Step 4: Joseph L. Proust proposed the law of definite proportions, which states that a given compound always contains the same elements in the same proportion by mass, but he is generally associated with one major law rather than two. Step 5: John Dalton later proposed atomic theory and the law of multiple proportions, building on earlier work including that of Lavoisier and Proust. Step 6: Rutherford worked in nuclear physics and experimental atomic structure, and Democritus was a philosopher with no experimental chemical laws. Step 7: Therefore the scientist who laid the foundation of chemical science by establishing two important laws of chemical combination is Antoine L. Lavoisier.

Verification / Alternative check:
In most school textbooks Lavoisier is given the title father of modern chemistry and is credited with establishing the law of conservation of mass and clarifying the concept of elements. He also helped move chemistry away from phlogiston theory towards an oxygen based understanding of combustion. When a question mentions foundation of chemical sciences and two important laws, it almost always points to Lavoisier, while Proust and Dalton are presented as later contributors who extended this foundation.

Why Other Options Are Wrong:
Joseph L. Proust contributed one key law, the law of definite proportions, but not two major laws. Ernest Rutherford is famous for his alpha scattering experiment and the nuclear model of the atom, not for laws of chemical combination. Democritus proposed the idea that matter is composed of indivisible atoms, but his ideas were philosophical and did not involve quantitative chemical laws. John Dalton developed atomic theory and the law of multiple proportions, but his work came after the fundamental mass based work of Lavoisier.

Common Pitfalls:
Students sometimes confuse Dalton and Lavoisier because both names appear frequently in early chapters. A simple way to remember is that Lavoisier focused on careful mass measurements and laws of conservation, while Dalton focused on a model of atoms and multiple proportions. Another pitfall is to choose Proust because the question mentions laws of chemical combination, but Proust is mainly linked with one law rather than a broader foundation of modern chemical science.

Final Answer:
The scientist who laid the foundation of modern chemical science by establishing two important laws of chemical combination is Antoine L. Lavoisier.