sentences: organic compounds do not contain potassium
docs: potassium_sulfate is inorganic_compound. potassium_phosphate is inorganic_substance. potassium is metallic_element. potassium_amide is inorganic_compound. potassium is element. potassium_nitrate is inorganic_compound. potassium_chloride is inorganic_compound. potassium_nitrite is inorganic_compound. potassium_bromide is inorganic_compound.