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Explanation:
The theory or working principle of Atomic Emission Spectroscopy involves the examination of the wavelengths of photons discharged by atoms and molecules as they transit from a high energy state to a low energy state. A characteristic set of wavelengths is emitted by each element or substance which depends on its electronic structure.
When Newlands tried to create a periodic table, his tried to conform to the "Rule of Octaves" he had discovered. He had the right idea, in that if you arrange the elements by atomic weight there would be similarities every 7 elements (not 8 because noble gases hadn't been discovered yet) but he tried to push this rule so much that he would put multiple elements in the same box to try to keep the rule. Mendeleev, however, left gaps in this table for undiscovered elements, which paved the way for our modern periodic table.
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Analytical Chemistry
Analytical Chemistry 2.1 (Harvey)
2: Basic Tools of Analytical Chemistry
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2.5: Preparing Solutions
Last updatedAug 10, 2020
2.4: Basic Equipment
2.6: Spreadsheets and Computational Software
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Contributed by David Harvey
Professor (Chemistry and Biochemistry) at DePauw University
Preparing a solution of known concentration is perhaps the most common activity in any analytical lab. The method for measuring out the solute and the solvent depend on the desired concentration and how exact the solution’s concentration needs to be known. Pipets and volumetric flasks are used when we need to know a solution’s exact concentration; graduated cylinders, beakers, and/or reagent bottles suffice when a concentrations need only be approximate. Two methods for preparing solutions are described in this section.
Equilibrium is dynamic since the reaction never really stops. There is still a forward and reverse reaction, their rates are just equal to each other so there is no observable change in the amounts of product or reactant making it look like the reaction has stopped.
This is why you will often here the term dynamic equilibrium used when describing a system in equilibrium.
I hope this helps. Let me know if anything is unclear.
