The Earth As A System

Question 1

Spheres of the Earth

Answer 1

Biosphere (bio means life)
•consists of all living organisms
•living organisms need gases from the atmosphere, water from the hydrosphere and nutrients from the lithosphere to survive

Atmosphere
•layer of air around the earth
•air is a mixture of gas(approximately 78% nitrogen, 21% oxygen and the rest of the air consists of carbon dioxide and other gases)
•the atmosphere is held around the earth by the force of gravity

Lithosphere(Litho means rocks)
•consists of all solid rock and soil
•covers the entire planet
•forms the solid part that makes up the land of the continents and the land below the oceans and seas
•all minerals and metals that are mined are part of the lithosphere

Hydrosphere (hydro means water)
•consists of all the water on Earth in all its different forms(solid liquid gas)
•about 97% of the earth’s water is salt water
•90% of the fresh water is frozen as once in the polar regions
•most water needed for human consumption is obtained from rain

Question 2

Types of rocks in the lithosphere

Answer 2

Igneous Rocks- Basalt and granite

Question 3

A rock that contains valuable minerals

Answer 3

Ore

Question 4

Identify a layer which has volcanic rock

Answer 4

The crust