How would an electron shell model of an oxygen atom (o) appear after the atom has formed chemical bonds?

a. it would have six electrons in the outermost shell.
b. it would have six electrons in the innermost shell.
c. it would have eight electrons in the outermost shell.
d. it would have eight electrons in the innermost shell.

oxygen atomic number is 8.

electron configuration of O is 2,6

therefore O has 6 valence electrons. valence electrons are electrons in the outermost shell that are involved in chemical bonds

atoms to become stable should fulfill the octet rule. This is where the outermost shell should have 8 electrons

so atoms with incompletely filled outer shells take part in chemical bonds to gain a complete octet and to become stable

So O too after forming a chemical bond would have 8 electrons in the outermost shell.

correct answer is

c. It would have eight electrons in the outermost shell.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.