Ilungu lekhemikhali liyi-substance enohlobo lwe-atom olunye kuphela. Ukuba i-substance ineentlobo zee-atoms ezimbini nangaphezulu, yi-compound. I-element isenokuba yi-solid, yi-liquid okanye onye i-gas. Eyona particle incinane ye-element elolo hlobo yi-atom. Ii-atoms zenziwe ngee- protons, ii-neutrons, nangee-electrons.