The total amount of mass-energy in a closed system cannot change. Energy can change from one form to another, Mass can change from one form to another, Energy can change to Mass, or Mass can change to Energy; but the total must remain constant.
Since Mass and Energy are traditionally measured in different units, we need a units conversion equation to tell us how much of each has changed to the other to get the equations right. Einstein provided us with that from his Special Relativity:
E = Mc2
If by the law of conservation you mean the Law of Conservation of Matter, then it states that matter cant be created or destroyed.
If by the law of conservation you mean the Law of Conservation of Matter, then it states that matter cant be created or destroyed.
The law of conservation of matter is applied to processes not to a compound.
The law of conservation of matter is also known as the law of conservation of mass. It states that mass is neither created nor destroyed in a chemical reaction, only rearranged.
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The law of conservation of matter states that in a chemical reaction, matter is neither created nor destroyed.
You are confusing the law of conservation of matter/mass with the law of conservation of energy. The law of conservation of matter/mass states that in a closed system matter is neither created nor destroyed. During a chemical reaction matter is rearranged, it doesn't change forms (energy can change forms). The atoms in the products are the same atoms that were in the reactants.
The law of conservation of matter
The law of conservation of matter states that matter is neither created nor destroyed. An example of this is a simple combustion reaction of methane. CH4 + 2O2 --> CO2 + 2H2O. There is 1 carbon, four oxygen's and four hydrogens on each side, thus showing conservation of matter.
condensation
The law of conservation of mass, which states that in a closed system, mass is neither created nor destroyed, it can only change form. This means that in a chemical reaction that takes place in a closed system, the mass of the reactants equals the mass of the products.
This is the Law of Conservation of Matter.