How can I write the formula for strontium fluoride?

1 Answer

The correct answer is Sr F2.

Let us see how we got the answer; Look at the electronic arrangement of Sr and F atom.

Sr ( Z= 38) has 38 electrons with following electronic configuration. 1s22s22p63s23p64s23d104p65s2

It loses two electron in its 5s subshell to achieve stability and forms ion Sr2+.

Sr2+ 1s22s22p63s23p64s23d104p6

F ( Z=9) on the other hand has nine electrons and wants to gain one more electron to achieve stable noble gas configuration.Fluorine atom on gaining one electron forms negative fluoride ion, F ion.

F( Z=9) = 1s22s22p5

F = 1s22s22p6

Two Fluorine atoms gains one electrons each ( total of two) from one Sr atoms, each Sr atom loses two electrons ( one each) to two chlorine atoms , in this process each Sr atom becomes Sr2+ ion and each fluorine atom after gaining one electron becomes F ion.

so in all we have one Sr2+ ions and two fluoride F ions.
so the formula becomes SrF2.

Simple to the point here: http://brainly.com/question/419669