What is Smog?

$(a)$ The temperature inside a glass enclosure is higher than that of the surroundings. Give a reason.
$(b)$ How is the above phenomenon utilized by cold countries to their advantage?
$(c)$ Name a greenhouse gas.

What is the percentage of oxygen found in the atmosphere? Name two compounds of oxygen found in nature. Name any three processes in which oxygen is used up in the atmosphere.

What causes acid rain? Mention any damage caused by it on living organisms.

The atmosphere of the earth is heated by radiations which are mainly:

What are the various forms in which oxygen is available?