He tauhohenga matū i waenganui i tētahi konganuku, te wai (H2O) me te hāora (O). Ka kainga te konganuku i tēnei tauhohenga matū. Hei tauira, ina pā te wai (H2O) me te hāora (O) ki te rino (Fe), ka waikura. He pōturi te tauhohenga o ngā ngota o ēnei matū e toru (te H2O, te O, me te Fe), ā, he hāura te tae o te putunga waikura ka puta i te mata o te rino.
A chemical reaction between a metal, water (H2O) and oxygen (O). The metal is eaten away in this chemical reaction. For example, iron will rust when exposed to oxygen and water. The reaction between the atoms of these three substances (H2O, O and Fe) is slow, and results in a browny rust on the surface of the iron.