Potassium is an alkali metal in group IA of the periodic table with atomic number 19, an atomic weight of 39.102, and a density of 0.86 Mg/m 3. Its melting point is 63.7 C, and it boils at 760 C. The ...

Rubidium is an alkali metal in group IA of the periodic table with atomic number 37, an atomic weight of 85.47, and a density of 1.53 Mg/m 3. Its melting point is 38.9 C, and it boils at 688 C. The ...