Why does magnesium have a higher melting point than sodium?
Both sodium and magnesium have metallic bonding between atoms. Outer electrons become delocalised and float freely between the positive ions. The positive ions attract the negatively charged electrons so the bond is very strong.Magnesium has a higher melting point because magnesium ions are Mg2+ and sodium is Na+. Magnesium ions have a stronger positive charge so the attraction to the delocalised electrons is stronger. There are also more delocalised electrons in magnesium than there is in sodium. This makes the metallic bonding in magnesium stronger so more energy is required to break it.
SC
Related Chemistry A Level answers
All answers ▸Briefly discuss Le Chatelier's Principle. Ammonia is made in the Haber Process (3H2(g) + N2(g)<-> 2NH3(g)). Using Le Chetelier's Principal, what happens to the equilibrium yield of ammonia when...: A) Temp increases, B) Press increases C) Catalyst changes
Imagine a reaction A for which the values of ΔH and ΔS are both negative. It is known that the absolute value of ΔS is 3 times smaller than the absolute value of ΔH. For what values of T does reaction A occur spontaneously?
How does ionisation energy vary across a period in the periodic table?
Calculate the concentration, in mol dm-3, of a solution of chloric (I) acid, HOCl , which has a pH of 4.23. Chloric acid is a weak acid, with Ka = 3.72 x 10^-8