GENERAL KNOWLEDGE

Detailed explanation-1: -The noble gases (historically known as inert gases; also known as aerogenes1) are a group of chemical elements with identical properties; they are all odourless, colourless, monatomic gases of very low chemical reactivity under normal conditions.

Detailed explanation-2: -The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity.

Detailed explanation-3: -Oxygen is the colourless, odourless gas which supports combustion.

Detailed explanation-4: -Noble gases are gases that are odourless, colorless, and tasteless under normal conditions and are made up of single atoms and have exceptionally low chemical reactivity.

Detailed explanation-5: -All noble gases are colorless and odorless. They also have low boiling points, explaining why they are gases at room temperature. Radon, at the bottom of the group, is radioactive, so it constantly decays to other elements.