Acid acid waa, dhab ahaantii, walax dabiici ah oo ka kooban atamka kaarboon. Atamyada kaarboon-tan kuma jiraan xaaladdooda oksaydhaynta ugu sarreysa, maadaama celceliska qiimahoodu uu yahay eber.
Sidaa darteed, oo leh shuruudo ku habboon, waxa ay qaadan kartaa oksaydh (oxidation by oxygen)., taasoo muujinaysa awooddeeda guban.