To draw the ionic Lewis structures for potassium fluoride (KF) and calcium oxide (CaO), we first need to understand the bonding in these compounds.
POTASSIUM FLUORIDE (KF)
1. **Identify the Atoms**: In KF, we have potassium (K) and fluorine (F). Potassium is in group 1, and fluorine is in group 17 of the periodic table.
2. **Determine the Ionic Charges**: Potassium will lose one electron to form a K+ ion, and fluorine will gain one electron to form an F– ion.
3. **Electron Configuration**: K has one electron in its outer shell that it can easily lose. F has seven electrons in its outer shell and needs one more to complete its octet.
4. **Lewis Structure**: We represent K+ as a K with no dots around it and F– with eight dots (representing its eight valence electrons). The complete structure can be represented as:
K+[F: .. .. .. .. .. .. .. .. ]
CALCIUM OXIDE (CaO)
1. **Identify the Atoms**: In CaO, we have calcium (Ca) and oxygen (O). Calcium is in group 2, and oxygen is in group 16.
2. **Determine the Ionic Charges**: Calcium will lose two electrons to form a Ca2+ ion, while oxygen will gain two electrons to form an O2- ion.
3. **Electron Configuration**: Ca has two electrons in its outer shell, which it will lose. O has six electrons in its outer shell and needs two more to complete its octet.
4. **Lewis Structure**: We represent Ca2+ as a Ca with no dots around it and O2- with eight dots. The complete structure can be expressed as:
Ca2+[O: .. .. .. .. .. .. .. .. ]
In summary, the ionic Lewis structures for KF and CaO allow us to visualize the transfer of electrons between the metal and non-metal atoms, resulting in the formation of ionic bonds.