Rangarira ndima iri pasi apa uye ipapo pindura mubvunzo gare gare mumutauro mumwe chetewo sechikamu:  Kupfuura: Midziyo yokutanga inoita kuti mhepo itonhore uye mafiriji yaishandisa magasi ane chepfu kana kuti anopisa, akadai seammonia, methyl chloride, kana kuti propane, ayo aigona kukonzera tsaona dzinouraya kana akadonha. Thomas Midgley, Jr. akagadzira gasi rokutanga risingatsvi, risina chepfu, rinonzi Freon, muna 1928. Zita iri zita rechiratidzo rakapihwa neDuPont kune chero chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), kana hydrofluorocarbon (HFC) inotonhorera. Mazita emvura inotonhorera anosanganisira nhamba inoratidza kuumbwa kwemamolecule (semuenzaniso, R-11, R-12, R-22, R-134A). Musanganiswa unoshandiswa zvikurusa mukutambanuka kwakananga kwemba nokuvaka kutonhodza kwokunyaradza iHCFC inozivikanwa sechlorodifluoromethane (R-22).  Mubvunzo: Mazita acho anoratidzei?
kuumbwa kwemamolecule