Question

Which of the following is not a fundamental law of conservation in nature?
A) law of conservation of mass
B) law of conservation of energy
C) law of conservation of linear momentum
D) law of conservation of angular momentum

Answer 1

Hint: A conservation law in physics asserts that a specific observable attribute of an isolated physical system does not change over time. Conservation of mass (now conservation of mass and energy thanks to Einstein's Theory of Relativity), conservation of linear momentum, conservation of angular momentum, and conservation of electric charge are all exact conservation rules. Mass, parity, lepton number, baryon number, strangeness, hypercharge, and other variables are all subject to approximation conservation rules. Certain kinds of physics processes, but not all, retain these quantities.

Complete answer:
The law of conservation of mass, also known as the principle of mass conservation in physics and chemistry, states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the mass of the system cannot change, and thus quantity cannot be added or removed. As a result, mass is preserved throughout time.
Processes that modify the physical or chemical characteristics of substances inside an isolated system (such as converting a liquid to a gas) keep the overall mass intact, implying that matter cannot be produced or destroyed. Mass is not a preserved quantity in the strictest sense. Except in nuclear processes, however, the conversion of rest mass into other kinds of mass-energy is so minimal that rest mass may be conceived of as preserved to a high degree of precision. The rules of mass and energy conservation can be merged into a single law, the conservation of mass-energy.
Hence option (A) is correct.

Note:
Mass, according to the law, cannot be produced or destroyed, however it may be rearranged in space and the things connected with it can change shape. In chemical reactions, for example, the mass of the chemical components before the reaction is the same as the mass of the components after the reaction. In an isolated system, the total mass of the reactants, or starting materials, must match the mass of the products throughout any chemical reaction and low-energy thermodynamic processes.