It is the first time that triangular bonding diagrams have appeared on the IB syllabus, although they have been on the Cambridge pre-U syllabus (another international examination for 16-19 year olds) for several years. I’m not convinced as to how useful they are. To me they do not really go much further than the old rule of thumb that if the electronegativity difference is greater than about 1.8 the compound is likely...