sodium and potassium  belong to alkali metals , group 1 on the periodic table
sodium is metallic_element. potassium_chloride is salt. sodium is alkaline_metal. potassium_phosphate is salt. group_2_elements is alkaline_earth_metals. potassium is element. one_of_chemical_elements is sodium. one_of_chemical_elements is potassium. group_1_elements is alkali_metals. potassium is alkaline_metal.