the question is:
MgO and NaF is iso-electronic.However,the lattice energy of MgO is almost four times that of NaF.This is because:
1.The charges on the ions in MgO are higher than the charges on the ions in NaF
2.The inter-ionic distance in MgO is shorter as compared with that in NaF
3.The hydration energy of the Mg2+ and O2- ion is more exothermic.
My teacher told me that the (1) ,(2) are true.but (3) is false.
I really dont get it why (2) is true,because at that time ,it is still an exam,so we only got a sheet of table periodic with us.And from it,i can just see that Na 's radius is larger than Mg,but O's radius is larger than F.
I dont know which one between MgO n NaF has shorter distance of interionic.
Can somebody tell me how to see that by just using table periodic or maybe some theory?
and also,I can't think why (3) is wrong..
2006-12-14
01:11:39
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1 answers
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asked by
Anonymous
in
Chemistry