How many electrons does fluorine have? How many electron shells? How many electrons are needed to fill the valence shell?

9 electrons when there is no charge shown. It has 2 shells, this is easy to see on the periodic table because it is in the second row. Otherwise you can count. There is 2 electrons on the inner shell then every shell after holds 8. Fluorine only has 9 electrons so 2 for the first shell and 7 on the outter shell. It needs 1 more electron to fill its outter (valence) shell.

Explanation:

the formula for the conversion of temperature from degree celsius to kelvin is:

the sample of water at is converted to kelvin temperature by using the above formula as:

on comparing the two samples of water at or we can say that at and at respectively. the difference between the temperatures of two samples of water is:

hence, one can say that the sample of water at is greater than the sample of water at by .