The group-14 elements silicon, germanium, tin and lead form anionic homometallic clusters that have been studied since the nineteenth century. They also form clusters with transition metals, in a ...

Technical drawing students and teachers were generally happy with the papers, but one question at higher level raised more than a few hackles. Pat O'Dwyer from Kenmare Vocational School, Co Kerry, ...

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They say that no two snowflakes are the same, but like all natural ice crystals they are only variations on the same six-sided theme. Now physicists have found the first evidence of pentagonal ice ...