Topic 4: Unit-3

Question 1

What is the stratosphere?

Answer 1

The second layer of the atmosphere, located above the troposphere and extending from about 10 km to 50 km above Earth.

Question 2

Stratosphere air density?

Answer 2

The air in this layer is less dense (much thinner) compared to the air in the troposphere

Question 3

Why do some aeroplanes fly in the lowest parts of the stratosphere?

Answer 3

the less dense air provides
- less friction
- enables faster speeds
- lower fuel consumption
avoid stormy weather patterns

Question 3

Upper stratosphere includes:

Answer 3

a band of ozone gas (O3) called the ozone layer

Question 4

How does temperature change in the stratosphere?

Answer 4

Temperature increases with altitude due to the absorption of ultraviolet (UV) radiation by the ozone layer.

Question 4

What is the ozone layer and why is it important?

Answer 4

A layer within the stratosphere that contains a high concentration of ozone (O₃), which absorbs and blocks harmful high energy UV radiation, thus protecting life on Earth from dangerous levels of radiation

Question 5

The further away from the earth…

Answer 5

the warmer the air becomes

Question 5

What are CFCs?

Answer 5

Chlorofluorocarbons (CFCs) are man-made chemicals used in aerosol sprays, refrigerants, and foam-blowing agents that destroy the ozone layer when released into the atmosphere. Resulted in the ozone layer becoming thinner, offering less protection against UV rays

Question 6

Excess UV radiation affects life on earth (4)
- H…
- P…
- L…
- Po…

Answer 6

• Human health - causes skin cancer, damages eyesight as well affecting the immune system
• Photosynthesis - kills plankton, the primary producer in almost all marine food chains and disturbs photosynthesis in plants
• Life Cycles - because depend on changing temperatures of seasons
• population size - plants & animals species by reducing the number of seedlings/offspring.