The ions of NaF and MgO all have the same number of electrons and internuclear distances are about the same (235 pm and 215 pm). Why are then the melting points of NaF and MgO so different `(992^(@) C and 2642^(@)C)` ?

The ions of NaF and MgO all have the same number of electrons and inte

1.	The ions of NaF and MgO all have the same number of electrons and internuclear distances are about the same (235 pm and 215 pm). Why are then the melting points of NaF and MgO so different `(992^(@) C and 2642^(@)C)` ?
Answer» In ` Mg^(2+)O^(2-)` , both ions carry two units of charge whereas in ` Na^(+) F^(-)` , each ions carries only one unit charge. Hence, eelctrostatic forces of attraction in MgO are stronger.

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The ions of NaF and MgO all have the same number of electrons and internuclear distances are about the same (235 pm and 215 pm). Why are then the melting points of NaF and MgO so different `(992^(@) C and 2642^(@)C)` ?

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