How can Lewis structures be used to determine the formula of ionic compounds? Give an example.
Solution 8E If we know the Lewis structure for an atom, we can even know the number of electron that can be transferred. This can be useful to determine the formula for a compound. Step 1 of 3 For example 2 2 6 1 Sodium (Na) has the following electronic configuration 1s 2s 2p 3s Thus it has only one electron in the Valence Shell (the one in 3s orbital) and can be represented as Instead of gaining 7 electron to complete the level number 3, the better is to lose the valence electron and leave out the energy level number 2, that is complete. Step 2 of 3 For Sulphur (S), we know that the electronic configuration is 1s , 2s , 2p ,3s , 3p . 6 2 4 Thus it has six electrons in the the Valence Shell (the one in 2 in the 3s orbital, 4 in the orbitals 3p) Thus Sulphur atom can be represented as So Sulphur atom needs 2 electrons to complete its shell. One electron can be given by a Sodium atom and another electron can be given by another atom of Sodium.