Which molecule is a stereoisomer of trans-2-pentene?

cis-2-pentene

Explanation : The stereoisomers are the compound which differs only in the spatial arrangement of the atoms across the stereogenic centers.

There are mainly two forms of stereoisomers cis and trans. Cis-isomers are those where the two bulky or functional groups are arranged on the same side across the stereogenic center; whereas, in trans-isomers the two bulky groups or functional groups are arranged in the opposite sides of stereogenic center.

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.

the correct answer would be d. hope this !