there is a negatively-charged whole of napkin
negatively_charged_amino_acid is not amino_acid. napkin is user_powered_device. glutamic_acid is not negatively_charged_amino_acid. napkin is not user_powered_device. napkin is not cleaning_tool. tea_napkin is not napkin. dinner_napkin is not napkin. sanitary_napkin is not pad. dinner_napkin is napkin. tea_napkin is napkin.