FORMULA OF IONS

1. Ionic compounds made up of positive ions and negative ions.
2. To write the formula of an ionic compound, we need to know the symbol and charge of the ions in the compound.
3. Periodic table are divided by group 1-18.
4. group 1-3 are likely to donate their electron so they will become +ions, while other group such as group 16-17 are more likely to receive electron so that they become -ions.
5. for example; sodium, Na is group 1 and when it react with other element from group 17 (eg. chloride, Cl), Na will become +ve ions because it donate 1 electron to achieve it stability and Cl will become -ve ions because it will receive the electron from Na and became stabil molecule.

here are example of formula of ions that we need to know:

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