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♔ Sunday, August 03, 2008
8:26 PM |
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went to tuition today...hmmm...LOVE IT!!! learnt about periodicity....its a WOW subject for me because its er, dunno? haha.... learnt about how the atomic radius can affect the reactivity and melting and boiling point of metal and non-metal elements...haha.... for metals ( grp 7), down the group, the atomic radius gets bigger, causing screening effect, thus the attraction between neutron and valence electron is weak, thus it has low metallic bond, causing the reactiving of the elements down group 7 to increase...haha..... for non-metals(group 1), as the atomic radius gets bigger, the greater contact surface, thus there is more Van Der Waal's force (intermolecular force), thus melting point and boiling point increases... haha... trying to memorise/understand what he is trying to say? but the charge density...i don't really understand... i think is down the period, the charge density increases, thus the atomic radius gets smaller? or something like that..dunno lar.... because too many to learn about periodicity...so i am just typing out to make me memorise...sorry...
went to parkway parade...nothing much...so tired because of dunno what reason...haha....want to sleep!!
