What is a fire extinguisher? What is the substance used in the modern type of fire extinguishers? How is it an improvement over the soda-acid and foam-type fire extinguishers?

Explain the term greenhouse effect. What are its benefits? How is it harmful?

What steps should be taken to balance carbon dioxide in the atmosphere?

Fill in the blanks:

(a) …………… is formed when carbon is burnt in a limited supply of air or oxygen.

(b) Carbon monoxide burns in air with a …………… flame to form carbon dioxide.

(c) Carbon monoxide is a product of …………… combustion.

(d) A mixture of 95% oxygen and 5% carbon dioxide is called ……………

(e) Carbon monoxide is used as a …………… in the extraction of pure metals from their corresponding ores.