The electronic structure for lithium is written as a list of numbers separated by commas is 2,1. This shows that lithium atoms have three electrons, two in the first shell and one in the second shell.

WHEN the electronic structure of matter had been demonstrated ... in which each ion is surrounded by six atoms of opposite sign; in crystals of the caesium chloride type, however, where the ...

Electron diffraction ... study the atomic structure of materials. It involves the interaction of a beam of electrons with a crystalline sample, resulting in a diffraction pattern that provides ...