an proton 78 is used for touch very big material by wash them appear bigger
proton_pump is tangible_thing. srm is not chemical_rocket. soft_copy is not matter. srm is not chemical_rocket_motor. atrazine is not chemical_compound. caesium_137 is solid. touch is somatosense. touch is small_indefinite_quantity. caesium_137 is not solid. soft_copy is matter.