Suppose you run a TLC and observe an Rf value consistent with the formation of the desired product. Next, you run a MP analysis and notice that a MP range is too large. Which of the following techniques would you implement? a. use a smaller amount of product for MP analysis
b. use a larger amount of product for MP analysis
c. rerun the TLC and change the mobile phase used
d. recrystallize the product

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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