 Solution

For the neutral aluminium cluster,This closes the listed sequence through 1I and supports the jellium description of a large metalloid cluster. Cp* ligands are counted as monovalent electron-withdrawing surface groups; counting each as a five-electron donor to the entire delocalized core would mix a transition-metal local electron-counting convention with the present shell model. Electron closure is a useful stability criterion, not by itself proof of a perfectly spherical nuclear geometry.