Modern periodic table is divided into 7 periods and 18 groups. Group 1(H, Li, Na, K, Rb, Cs, Fr) is the longest group in the periodic table. The first group is called the alkali metals group.
Group I-Alkali Metals
Listed below are few features of alkali metals
- The elements in the first group, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr) are called alkali metals.
- They were given the name because they all react with water to form alkalis.
- The alkali metals are all shiny, soft, highly reactive solids at standard temperature and pressure and readily lose their outermost electron to form cations with charge +1.
- Number of valence electrons = 1