How can I write the formula for strontium fluoride?

1 Answer
Manish Bhardwaj · Media Owl
Jul 3, 2014

The correct answer is #Sr# #F_2#.

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. 1#s^2#2#s^2#2#p^6#3#s^2#3#p^6#4#s^2#3#d^10#4#p^6#5#s^2#

It loses two electron in its 5s subshell to achieve stability and forms ion #Sr^(2+)#.

#Sr^(2+)# 1#s^2#2#s^2#2#p^6#3#s^2#3#p^6#4#s^2#3#d^10#4#p^6#

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) = 1#s^2#2#s^2#2#p^5#

#F^-# = 1#s^2#2#s^2#2#p^6#

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 #Sr^(2+)# ion and each fluorine atom after gaining one electron becomes #F^-# ion.

so in all we have one #Sr^(2+)# ions and two fluoride #F^-# ions.
so the formula becomes Sr#F_2#.

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

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