Which element has a complete valence electron shell? selenium (se) oxygen (o) fluorine (f) argon (ar)

Argon (Ar)

Explanation:

Atomic number of selenium = 34

Electronic configuration of Se =

So, its valence shell is not complete.

Atomic number of oxygen = 8

Electronic configuration of O =

So, its valence shell is also not complete.

Atomic number of fluorine = 9

Electronic configuration of O =

So, its valence shell is also not complete.

Atomic number of argon = 18

Electronic configuration of O =

So, its valence shell is complete.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds