For the four sentence (S1-S4) paragraph given below, sentences S1 and S4 are given. From the options P, Q and R, choose appropriate sentences for S2 and S3 respectively.

S1: Once the oppositely charged ions form, they are attracted by their positive and negative charges creating an ionic bond and thus forming an ionic compound.

S2: ___________

S3: ___________

S4: The creation of an ionic bond between a metal atom (sodium) and a nonmetal (fluorine) is an example of this.

Options:

P. This difference causes an unequal sharing of electrons such that one atom completely loses one or more electrons and the other atom gains one or more electrons.

Q. Ionic bonds are also formed when there is a large electronegativity difference between two atoms. 

R. The octet rule states that an atom is most stable when there are eight electrons in its valence shell.