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.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.