What are the physical properties of carbon monoxide ?

Explanation

### Step-by-Step Text Solution:

1. **Definition of Carbon Monoxide**: Carbon monoxide (CO) is a colorless, odorless gas that is produced by the incomplete combustion of carbon-containing fuels.

2. **Poisonous Nature**: One of the most critical physical properties of carbon monoxide is that it is highly poisonous. It binds with hemoglobin in the blood to form carboxyhemoglobin, which is much more stable than the oxygen-hemoglobin complex. This reduces the blood's ability to carry oxygen, leading to suffocation.

3. **Odorless**: Carbon monoxide is odorless, meaning it does not have any smell. This property makes it particularly dangerous, as people may not realize they are being exposed to it.

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