UHowo

Izinhlayiyana zentuthu ezilezayo zikhomba umdiki wohowo oluzungezile

uHowo luyingxenye yezimo zoTho eziyisisekelo (ezinye zihlanganisa ukuNquma, uketshezi kanye noNyazani). Uhowo okucwebile lungakhiwa amachwe ngamanye (isb. uhowo lwekhethelo inkanyihwe), amachembe enhlwa akhiwa ichwe lohlobo olulodwa (isv. IsOhwe), noma umxube wamachembe akhiwa amachwe ahlukene (isb. UmCalahle ontuhlambili). Uhowo luwumvubo, ofana nomoya, oqukethe ohowo abacwebile abahlukene. Into ehlukanisa uhowo eketshezini nasemikhumenqeni ukwehlukana okukhulu kwezinhlayiyana ngazinye zohowo. Lokhu kwahlukana imvama kwenza uhowo olungenambala lungabonakali emehlweni omuntu.

Isimo esiluhowo sotho senzeka phakathi kwesimo esiluketshezi nesimo esilunyazani, esakamuva okuyisona esinikeza umkhawulo ophezulu wezingalokushisa kohowo.

 Izinhlwa eziwuhowo 
Izinhlwa zevanga eziwuhowo olunomzwayi ochwembili (diatomic) elindeninye (homonuclear) enozinzo ngokwe-STP yilezi:
IHwanzi (H2), INihwe (N2), IsOhwe (O2), kanye nezakhatshiwo (halogens) ezimbili: UFusihwe (F2)  neChwenzi (Cl2). Lapho ziqembulwa ndawonye nohowo lwekhethelo olunechwelinye – IHwelanga (He), iNkanyihwe (Ne), IsAlahwe (Ar), umKhalahwe (Kr), IXhwe (Xe), and umLahwe (Rn) – loluhowo lolunke lubizwa ngokuthi "izinhlwa eziwuhowo".