THE FIRST ATOM WITH BOTH INNER AND OUTER ELECTRONS

LITHIUM, THE FIRST ATOM WITH BOTH INNER AND OUTER ELECTRONS 

The third element in the periodic table is lithium, Li, atomic number 3, atomic mass 6.941. The most abundant lithium isotope has 4 neutrons in its nucleus, so it has a mass number of 7 and is designated gLi. A less common isotope, gLi, has only 3 neutrons. 

Lithium is the first element in the periodic table that is a metal. Lithium is the lightest metal, with a density of only 0.531 g/cm. As mentioned in Section 2.2, metals tend to have the following properties  

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Section 3.8. Lithium, The First Atom with Both Inner and Outer Electrons... 

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