Cbse | Air And Its Components

A certain vector in the xy plane has an x-component of 12 m and a y-component of 8m. Its then rotated in the xy plane so that its x-component is halved. Then its new y-component is approximately :

Thought air contains only about 0.03% of carbon dioxide , it is a very important component of air. Give reasons.

What are the major components of air ? Among these , which is the active component and which is the inactive component ? Give any four characteristics of air as a mixture.