The Organometallic HyperTextBook: Electron Counting. The 18 electron rule Just as organic chemists have their octet rule for organic compounds, so do organometallic chemists have the 18 electron rule.
And just as the octet rule is often violated, so is the 18 electron rule. However, both serve a useful purpose in predicting reactivity. Some help when googling. Students: seize the day, and do some work. Nothing better to do?
Photograph: Alamy The spectre of the second term, with its attendant horrors of essay deadlines and January exams, is looming. But as we reflect on the negligible amount of work we completed over the Christmas break, let's soberly consider our new year's resolutions. Natural Sciences Tripos: Structure of the course. The Tripos is taught in three (or four) large blocks, called Parts.
At the end of each year, students sit examinations in the courses they have taken for that Part. Students are expected to progress through the Tripos throughout their undergraduate education: most students increasingly specialise in a single subject area by Part II, although opportunities to retain a broad study of science exist (Biological and Biomedical Sciences and Physical Sciences). Further information on each subject is available in the programme specification, on the course website, and in the subject summary. These pages provide an outline of each Part of the Tripos and include essential advice and information for the start of each year.