Astudent is comparing two samples of crystalline organic solids. a tlc analysis shows a single spot for each sample and the co-spot with the same rf value. which of the following would provide the most conclusive evidence that the two samples are the same compound?
-rerun the tlc using more developing solvent
-rerun the tlc on a longer tlc plate
-perform a mixture melting point
-mix the substances and run the tlc as a single spot

Rerun the TLC using more developing solvent

Explanation:

The TLC principle envolves the interaction of the samples with the solvent and the stationary phase.

For the solvent you are using at the moment, the interaction with the sample may be very similar for both cases depending with the polarity, what could indicate an equal value.

If you develops a new solvent with a different polarity, you can see if the samples are the same compound or not. Because a more polar compound will interact more with the stationary phase and a more non-polar compound will interact more with the solvent.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.