ABSTRACT
The properties of alkali metal compounds vary systematically, particularly the properties of Potassium, Rubidium, and Cesium. Sodium does not deviate from the regular trends nearly as much as Li does. In many of its properties, Li is quite different from the other alkali metals. Some compounds of lithium, such as fluoride, carbonate, and phosphate, are relatively insoluble, and those of the other alkali metals are reasonably soluble. The solubility of these compounds of lithium increases in the presence of acid by forming acid salts. Because of their smallness and high charge density, the lithium compounds, having significantly higher lattice energies, are much more stable than the corresponding sodium compounds. Lithium hydride is stable at atomospheric pressure to 800 to 900°C, whereas sodium hydride decomposes at 350°C. Lithium is the only alkali metal that reacts with N2 gas. Li3N is very stable, whereas Na3N is unstable at room temperature.
