What is corbonmonoxide?

Answer 1

CO

"half burned carbon"

Carbon can (and will) join with two oxygen atoms to form carbon dioxide when burnt.

If there is a shortage of oxygen then the carbon will "half burn".

CO is n odorless gas that is extremely toxic.

Answer 2

Carbon monoxide is a colorless, odorless gas that is produced by the incomplete burning of carbon-containing fuels, such as gasoline, natural gas, and wood. It is highly toxic when inhaled as it binds to hemoglobin in the blood, preventing oxygen from being transported to cells in the body. Symptoms of carbon monoxide poisoning include headache, dizziness, nausea, and confusion.