甚麼chemical有choking smell?

其實這裡有點分歧，因為同一本書都會有唔同的形容詞，以下的謹作參考。

Chlorine: choking smell, swimming pool smell
Ammonia: Pungent choking smell
Sulphur dioxide: choking smell

至於hydrogen sulphide我便不知道了

For correcting the above

Hydrogen sulphide is not choking smell !
The better description would be " Bad egg smell "

Actually, Sulphur dioxide SO2 also has a choking and pungent smell

Chlorine (氯) 肯定對.

Bromine (溴) 也應該對.

你有沒有學過 Hydrogen Sulphide (硫化氫)? 有的話也可以.