Write the Lewis symbols that represent the ions in each ionic compound.
Step-by-step solution Step 1 of 5 Lewis structures: Valence electrons of the main group elements are represented as the dots surrounding the symbol of the element in Lewis structures of atoms or ions. Step 2 of 5 a) Explain the formula SrO Strontium (Sr) belongs to II A group, thus it has two electrons in its outer shell Oxygen (O) belongs to VI A group thus it has six electron in its outer shell. So we can represent them using the Lewis structures Because of the Oxygen’s high electronegativity respect to Strontium, Oxygen can gain electrons from Strontium. In order to reach their stability, Strontium can give two electrons to Oxygen, thus leaving the inner shell complete. On the other hand, Oxygen can gain two electrons from strontium, completing its outer shell. This is the reason why Sr and O combine together in a 1:1 ratio, thus obtaining the formula SrO. Strontium turns to be a positive, bivalent, ion (because it loses two electrons) Oxygen becomes a negative, bivalent ion (because it acquires two electron). Thus the Lewis formula is Step 3 of 5 b) Let’s explain Li S 2 Litium (Li) belongs to I A group, thus it has one electron in its outer shell Sulphur (S) belongs to VI A group thus it has six electrons in its outer shell. Because of the Sulphur’s high electronegativity respect to Litium, Sulphur can gain an electron from Litium. We can see the Lewis formula for the atoms as they are in the picture below Unfortunately, when an atom of Li loses its outer electron, it becomes so stable that cannot lose another one; Sulphur instead needs another electron to complete the outer shell. This last electron can be supplied by another atom of Litium, thus Litium and Sulphur combine themselves in a 2:1 ratio. The final formula will be Li S 2 Litium turns to be a positive, monovalent, ion (because every atom loses a single electron) Sulphur becomes a negative, bivalent ion (because it acquires two electron). Thus the Lewis formula for this compound is