In chemistry the need for standards when measuring quantities are in place for accurate measurement that is recognized world wide. This way, no matter what language people use, they will always understand there standards.
Explanation:
(1). It is known that in a reaction equation, reactants are placed or written on left hand side and products are written on the right hand side.
For example, 
Hence, in a reaction equation you start with the reactants and end up with the products.
(2). The number of atoms in a reaction will remain the same because according to the law of conservation of mass, mass of reactants will be equal to the mass of products.
Therefore, number of atoms on the reactant side will be equal to the number of atoms on product side.
Ah, this is actually a fairly simple chemistry question.
Recall that at STP, one mole is equivalent to 22.4 L. Knowing this, all you have to do is divide 500 L by 22.4 L to find the number of moles:
500/22.4 = 22.3 mol
-T.B.
Answer:
Nucleus,mitochondria,& cell membrane
Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.