I-Substance yi material, noma yi matter, okuyiyo esetshenziswa ekwakheni into ethize. Ama-substance izinto ezi physical ezibonwayo, ezithintekayo, noma ezikalekayo. Zenziwe yi elemental part eyodwa noma amaningi. Insimbi, yi aluminiyamu, amanzi kanye nomoya ngumzekelo wama substances. Le-athikhili iyisigcino (isiNgisi: "a stub"). Ungakwazi ukusiza uWikipedia: ngokuyikhulisa.