Check the Shells: Always ensure you only draw the outer shell unless the question specifically asks for all shells. Drawing inner shells often leads to clutter and mistakes in counting.
Verify Charge Balance: A common way to lose marks is forgetting that the total positive and negative charges must sum to zero. If you have a ion, you must show two ions in your diagram or formula.
Bracket Placement: Ensure the charge is outside the square brackets. Placing it inside suggests it belongs to a specific nucleus rather than the whole ion.
Noble Gas Check: After the transfer, the non-metal ion should almost always have exactly 8 electrons (a mix of dots and crosses) in its outer shell.
Sharing vs. Transfer: Students often mistakenly draw overlapping circles for ionic compounds. Remember: if there are brackets and charges, there should be no overlap.
Incorrect Ion Charges: Ensure the charge corresponds to the number of electrons lost or gained. Losing 2 electrons results in a charge, not .
Empty Shells: When a metal loses its valence electrons, its 'new' outer shell is the full shell beneath it. In diagrams, we often represent the metal ion as a circle with no electrons to show the original valence shell is now empty.
