Which gas is known to be colorless, odorless, and tasteless but very dangerous?

The gas known to be colorless, odorless, and tasteless but very dangerous is carbon monoxide. This gas is produced during the incomplete combustion of fossil fuels and can accumulate in enclosed spaces, posing a significant health threat. The lack of sensory cues such as color, smell, or taste makes carbon monoxide particularly hazardous because individuals can be exposed to it without realizing it, leading to poisoning that can result in serious health effects or even death.

In comparison, the other gases listed have distinctive characteristics. Ammonia has a strong, pungent odor, chlorine is yellow-green and has a sharp smell, and hydrogen cyanide, while also dangerous, is known for its bitter almond scent, which some people can detect. This sensory awareness about the other gases makes them less insidious than carbon monoxide, highlighting the importance of proper ventilation and detection systems in environments where these gases may be present.