Hydrogen and the Alkali Metals

For hydrogen and the alkali metal atoms in their ground configurations, or excited configurations involving promotion of the valence electron, there is only one electron with an unpaired spin. For this electron = - - or — and the corresponding electron spin part... 

Kernoghan, A.A. (1996). Positron scattering by atomic hydrogen and the alkali metals. Ph.D. thesis, Queens s University of Belfast. 

In peroxides, the oxidation number of oxygen IS -1, and in superoxides, it is -5. The only common superoxides are those of hydrogen and the alkali metals from potassium through francium. Peroxides occur with hydrogen, sodium, barium, and chromium, and in these compounds, each of these elements exists in its highest oxidation state. 

If we consider the vertical columns instead of the horizontal rows, we find elements with similar chemical properties listed one below the other. Group I, for example, includes hydrogen and the alkali metals like lithium and sodium. Group III includes scandium, yttrium and all the lanthanide and actinide elements. 

He fits the ether element into his Periodic Table in the manner shown in Figure 305. Mendeleev placed the inert gases in Group 0, to the left of hydrogen and the alkali metals. This places helium in Period 2 and leaves a gap to the left of hydrogen in Period 1. Our modern Periodic Tables place the inert gases in Group 18 (8A in some versions) and thus helium now sits in Period 1 for reasons... 

For systems other than singlets, g is not equal to 1. In this case, a more complicated splitting occurs the anomalous Zeeman effect. For example, consider the doublet system in hydrogen and the alkali metals. The lowest term is 5 /2 For this term, L = 0, J = S = therefore Mj = i, — i and g = 2. The product gMj = 2( ) = 1. Using this value in Eq. (24.49) we obtain... 

The elements in group 1 are hydrogen and the alkali metals lithium li, sodium Na, potassium K, rubidium Rb, cesium Cs and francium Fr. The last one, francium, was discovered in 1939 by Marguerite Percy in Paris. It will be described in Chapter 52 The Radioactive Elements. The others wiU be treated in this and the following two chapters. 

---