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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: chun02080 on November 10, 2008, 11:31:02 AM

Title: something about the melting point of magnesium among group 2
Post by: chun02080 on November 10, 2008, 11:31:02 AM

I want to ask why the melting point of magnesium would be the lowest among the Group two metal..

since magnesium has smaller siza than Ca and Sr ..i don't know why the Mg would have the lowest melting point

Title: Re: something about the melting point of magnesium among group 2
Post by: Astrokel on November 10, 2008, 01:58:50 PM

Hey chun02080, when comes to melting point, always first look at the efficiency in packing of the atoms. Do you know the structures of all the group II metals?

Title: Re: something about the melting point of magnesium among group 2
Post by: chun02080 on November 11, 2008, 02:20:06 AM

ya
Of course i know the structure of the group two metal
the Be and Mg have the h.c.p.
whereas have the c.c.p.
and Ba have the b.c.c

but how this structure would make the difference of the melting point of these metal

is it because of the packing efficiency????

but then why the Ba would have higher melting point than the magnesium
the Ba only have b.c.c and only have packing efficiency of 68%
if it really determined by the packing efficiency ..it would have contradicion!
plz help me  :'( ??? ??? ??? ??? ??? ??? ??? ???