Q1-4:

The diagram below shows the internal structure of the Earth.

1. What is the name given to layer X?

• A. The crust
• B. The middle core
• C. The mantle
• D. The metamorphic layer

2. What is the name given to layer Y?

• A. The crust
• B. The middle core
• C. The mantle
• D. The metamorphic layer

3. Which layer is thought to be liquid?

• A. The atmosphere
• B. The outer core
• C. The mantle
• D. The inner core

4. Which layer(s) are thought to contain mostly iron and nickel?

• A. The crust
• B. The outer and inner core
• C. The mantle and outer core
• D. The mantle

5. The Earth's atmosphere contains oxygen, which we breathe. Which of the answers below gives the approximate percentage of oxygen in the atmosphere?

• A. 10%
• B. 20%
• C. 30%
• D. 40%

? < A B C D

6. Which gas is the most abundant in the Earth's atmosphere?

• A. oxygen
• B. argon
• C. carbon dioxide
• D. nitrogen

Q7-8.
Scientists are worried about global warming. As we burn fossil fuels, we are trapping more heat energy in the atmosphere.

7. Which gas is released into the atmosphere when we burn fossil fuels?

• A. carbon dioxide
• B. oxygen
• C. methane
• D. hydrogen

8. The process of some gases 'trapping' infrared heat in the atmosphere is called..

• A. insulation
• B. the greenhouse effect
• C. the ozone layer
• D. the convection cycle

9. One process that can remove carbon dioxide from the atmosphere is..

• A. respiration from living things
• B. photosynthesis
• C. burning renewable resources like wood
• D. the effect of sunlight

10. Fossil fuels like coal and oil are all part of the carbon cycle. The source of carbon in fossil fuels is..

• A. the Sun
• B. volcanic gas emissions
• C. sedimentary rocks
• D. fossilised plants and animals