what is the law of conservaton of mass?

Answer 1

http://en.wikipedia.org/wiki/Law_of_conservation_of_mass

You're welcome. :]

Answer 2

The law of conservation means what you invest in is what you get out.
Masses are usually in the form of structure. In Chemical reation and nuclear reaction the amount of mass invested is not allways equal to the product.
The reason in a reaction mass is lost to the suroundings. However the losses are so small that in chemical calculation the mass loss is neglected.Therefore the reactant is closely equal to the product of the reaction.

If the Universe is a closed finite system than mass is conserved.
The reason is that the masses lost out of the galaxies go nowhere outside the Universe or are reabsobed into other galaxies. So If the mass cannot leave a closed system the total mass containment is conserved(it does not change).

Answer 3

The law of conservation of mass/matter, aka Law of Mass Conservation (or the Lomonosov-Lavoisier law), states that the mass of a closed system of substances will remain constant, regardless of the processes acting inside the system. An equivalent statement is that matter changes form, but cannot be created nor destroyed. This implies that for any chemical process in a closed system, the mass of the reactants must equal the mass of the products.

Answer 4

It states that mass of a substance always remains the constant regardless the chemical reactions taking place in it....i.e.
the total mass in the reactants is always equal to the total mass in
product

Answer 5

no matter can be created or destroyed...but u can change the form of it