At high temperatures, alkanes can undergo dehydrogenation to produce alkenes. For example: This reaction is used industrially to prepare ethylene while simultaneously serving as a source of hydrogen gas. Explain why dehydrogenation only works at high temperatures.

Dehydrogenation of alkanes is endothermic

Explanation:

The dehydrogenation of alkanes is an endothermic reaction. The enthalpy change for the reaction is highly positive.

Recall that for an endothermic reaction, increase in temperature increases the rate of forward reaction.

As a result of that, the dehydrogenation of alkanes proceeds in the foward direction at elevated temperatures.

beta decay is the answer

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.