sometimes I pronounce it as "carbon dioxide", but seems too complex and not very exact in chemical way. Can it be pronounced as "C-O-two"? Thanks.
2 -> di-
O -> -oxide
Some names of chemicals (especially older ones) are inexact: the word 'saltpetre' doesn't tell you much, for example. The modern equivalent, 'potassium nitrate' does - though not as much as 'carbon dioxide', which is a model of clarity