Which of the following gases is a major contributor to the greenhouse effect? MCQ with Answer and Explanation

Explanation:
Bakelite, the first fully synthetic plastic, is a thermosetting phenol formaldehyde resin. It is formed by a condensation reaction between phenol and formaldehyde. Once molded and heated, it sets permanently and cannot be remelted. It is used for electrical switches, utensil handles, and jewelry.

Explanation:
Charles Goodyear accidentally discovered vulcanization (heating rubber with sulfur) in 1839, which improved rubber's elasticity and strength. Dunlop invented pneumatic tire; Baekeland invented Bakelite; Carothers nylon.

Explanation:
The stratospheric ozone layer absorbs the majority of the sun's harmful ultraviolet (UV-B and UV-C) radiation, preventing it from reaching Earth's surface. UV can cause skin cancer, cataracts, and damage to ecosystems. Ozone depletion is caused by CFCs (chlorofluorocarbons). Infrared is associated with heat, visible light is mostly harmless, radio waves are not absorbed by ozone.