Question #7ddac

Conservation of mass is a fundamental law in chemistry and is a cornerstone of the atomic theory.

However, one thing we must admit in science is that any theory must be subject to testing that could potentially prove the theory to be incorrect.

In fact, if we broaden out into nuclear physics and take of nuclear fission and fusion, even atoms can be created and destroyed (changed into other atoms).

....and at the moment, the model that includes the concept that matter and energy cannot be created nor destroyed appears to work.

What science actually says (1st law of thermodynamics) is that the "total energy in a closed system cannot be created nor destroyed", although it can be changed from one form to another. Following Einsteins work it was realised that the 1st law of thermdynamics also applied to mass, and that mass could be essentially regarded as another type of energy that needed to be incorporated into a thorough thermodynamic treatment of a system.

However, from a quantum mechanics perspective, on EXTREMELY small timescales, for an EXTREMELY short length of time, energy can indeed be spontaneously created and destroyed. But on a normal "human observed" timescale, everything averages out to what the 1st law of thermodynamics says should be true.

So at present, with our current understanding of physics, a model that says "matter cannot be created or destroyed" seems to fit with observations well. But as our knowledge of physics develops further, maybe models needs to be revised, who knows?