there is a negatively-charged whole of napkin
aspartic_acid is negatively_charged_amino_acid. napkin is cleaning_tool. dinner_napkin is napkin. tea_napkin is napkin. sanitary_napkin is pad. napkin is user_powered_device. person_using_napkin has probably_just_eaten napkin_ring is non_powered_device. glutamic_acid is negatively_charged_amino_acid. negatively_charged_amino_acid is amino_acid.