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Natural sciences

Planet earth and the universe

The earth

Educator section


Leaner section


Activity: to represent the different layers in the earth’s atmosphere visually and to investigate weather patterns and seasons [lo 2.3, lo 3.1]


A layer of air called atmosphere envelops the earth. This layer usually contains two gases, namely oxygen (78%) and nitrogen (20%). The atmosphere consists of a number of layers, of which each has its own characteristics.


  • Troposphere

This is the layer closest to Earth. Here we find all the weather patterns and clouds, and this is also where aeroplanes and birds fly.

  • Ozone layer

The harmful ultra-violet rays of the sun are absorbed in this layer.

  • Stratosphere

It is here that modern jets fly. Oxygen supply is insufficient for man to breathe.

  • Mesosphere

Most small meteors burn out in this layer.

  • Thermosphere

Most of the sun’s heat is absorbed here; temperatures rise to 1 000 degrees Celsius.

  • Ecosphere

There is almost no air in this layer. Only the lightest of gases are found here, as well as some weather satellites.

The above-mentioned layers do not have fixed limits and we can therefore say that they intermingle. The density decreases the higher the layer is until almost no air is present. Compared to the cross-section of the earth, the atmosphere is not really a very thick layer.


Group work

  • Using the information given, make a diagrammatical representation of Earth, showing all its layers.
  • Use different colours to distinguish between the layers.
  • Labels must be in print.
  • The thickness of layers must be displayed.
Educator Assessment: Diagrammatical Rrepresentation 1. 2. 3. 4.
1. Aim: The message is carried over clearly
2. Detail: Detail is accurate and clear
3. Sketches and illustrations: Functional and purposeful
4. Creativity: Representation is creative and original
5. Presentation: neat and orderly
DOMINANT CODE: ........MARK: ......./ 20 ..............%Educator:..................................................






Learner: _____________________________________________________________


Learning Outcome 2: The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard 2.3: We know this when the learner interprets information: interprets information by identifying key ideas in text, finding patterns in recorded data, and making inferences from information in various forms (e.g. pictures, diagrams, text).

Learning Outcome 3: The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

Assessment Standard 3.1: We know this when the learner understands science as a human endeavour: compares differing interpretations of events.

Questions & Answers

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s. Reply
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s. Reply
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s. Reply
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Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
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In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
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Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
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Smarajit Reply
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Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
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