Question

Which of the following statements is a natural law? (a) The total mass of reacting substances remains constant after reaction. (b) The total energy of two gas molecules remains constant after colliding. (c) The volumes of two gases combine in the ratio of small whole numbers. (d) The nucleus of an atom contains protons and neutrons.

Short answer

(a) The total mass of reacting substances remains constant after reaction.

Step-by-step solution

Define Natural Law

A natural law is a statement that describes an observable regularity in nature, often formulated as a statement or a mathematical formula that describes such regularity.

Analyze Option (a)

Option (a) states 'The total mass of reacting substances remains constant after reaction.' This refers to the Law of Conservation of Mass, which is a fundamental principle in chemistry that reflects a natural law.

Analyze Option (b)

Option (b) states 'The total energy of two gas molecules remains constant after colliding.' This is related to the conservation of energy, another fundamental principle in physics; however, it fails to generally describe a specific natural law in the way option (a) does.

Analyze Option (c)

Option (c) states 'The volumes of two gases combine in the ratio of small whole numbers.' This describes the law of combining volumes, which reflects a more specific chemical behavior but is less commonly recognized as a fundamental natural law compared to mass conservation.

Analyze Option (d)

Option (d) states 'The nucleus of an atom contains protons and neutrons.' This is a scientific fact, not necessarily a natural law, as it describes the composition of atomic particles rather than an observable regularity in the universe.

Make the Conclusion

As natural laws typically identify fundamental principles that describe consistent observations, option (a), 'The total mass of reacting substances remains constant after reaction,' is the most fitting to be classified as a natural law due to its recognition as the Law of Conservation of Mass.

Key concepts

Law of Conservation of Mass

One of the core principles in chemistry is the Law of Conservation of Mass. This law asserts that in a closed system, the total mass of substances involved in any chemical reaction remains unchanged. During chemical reactions, while substances undergo changes to form new products, the sum of the mass of the reactants equals the sum of the mass of the products.

• This concept is fundamental because it emphasizes that matter is neither created nor destroyed in chemical processes.
• Instead, atoms are simply rearranged to form new substances.
• It helps chemists understand and predict the outcomes of reactions.

For example, if you were to combine two types of gases in a sealed container, the total mass before and after the reaction would be the same. The idea was first articulated by Antoine Lavoisier in the 18th century, and it laid the groundwork for modern chemistry by creating a framework for understanding chemical equations and reactions.

Observable Regularity

Observable regularities are patterns or consistencies that occur in nature, allowing scientists to formulate laws or principles. When scientists observe a repeated phenomenon under consistent conditions, they can begin to describe this occurrence through natural laws.

• Naturally occurring events, like the change of seasons or the phases of the moon, are classic examples of observable regularities.
• These regularities provide predictability and enable the scientific community to make informed deductions about the natural world.
• Science relies on observable regularities as a basis for formulating theories and models that explain how the world functions.

Understanding these regularities is essential for developing scientific knowledge and applying it practically, such as in developing new technologies or addressing environmental changes.

Natural Principles

Natural principles are the basic guidelines or truths that underline how our universe operates. These principles form the foundation upon which scientific knowledge is built. They are broad and can encompass laws, theories, and facts that have been repeatedly verified through observation and experimentation.

• The principles act as a roadmap for scientists, guiding research and experimentation.
• They include well-established concepts like gravity, thermodynamics, and electromagnetism.
• The role of a scientist often involves testing these principles under varying conditions to understand their applicability and extend their explanation through new discoveries.

While natural laws describe consistent observations, natural principles encompass not just laws but also explain why or how these phenomena occur. Thus, they are pivotal in expanding scientific inquiry and technological advancements.