Which of the following molecules contains a polar covalent bond?

a. o2
b. n2
c. co
d. h2

CO contains a polar bond.

Explanation:

CO has a polar bond because of the electronegativity difference between the C and O atom. According to Pauling scale the electronegativity value of C and O are 2.5 and 3.5 respectively. So the electronegativity difference in C-O bond is (3.5 – 2.5)1.0, which greater than 0.5 and hence polar.

O₂, N₂ and H₂ do not have polar bonds as there is no electronegativity difference between two atoms of the same element.

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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