Unit 4 We save natural resources

 

    Unit 4 We save natural resources

   What are the spheres of the Earth?

  The Earth can be divided into 4 spheres: Geosphere, hydrosphere, atmosphere and biosphere.

 Geosphere: The rocky part of the planet. It can be divided into 3 different parts.

Atmosphere: It is a layer of gases that protects the Earth and allow us to breath oxygen.

Biosphere: It is the sphere of the Earth where the living things are. The different ecosystems of the Earth compose the biosphere.

Hydrosphere: It is the sphere that includes all the bodies of water of the planet.

How does the surface of the Earth change?

The surface of the Earth changes over time. There are some physical or chemical processes that influence :

a) Breaking down rocks: Frost, chemical components, heat and living things(trees or animals) can break down rocks of the surface of the Earth

b) Erosion: materials of rocks and soil are removed from the action of the water and the wind.

c) Transport: Water and wind can transport the eroded materials from one part to another

d) Deposition: the materials are deposited in one place when the action of water or wind ceased.

 What are rocks and how are they formed?

What are minerals?

Properties of minerals

Every mineral has specific properties. Here we are going to learn about:

1) Colour: Every mineral has an specific colour.

2) Density: It is the relationship between mass and volume of the mineral.

3) Shape: Some minerals can have regular shapes. 

4) Lustre: How shiny is a mineral.

5) Hardness: How easy or difficult is to break the mineral into smaller parts. Some minerals are very hard (diamond) or very soft (talc)