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Natural sciences

Planet earth and the universe

The earth

Educator section

Memorandum

Assignment 1:

  • Assess using the assessment matrix.

Assignment 2:

Main Ideas

  • Earthquake: evening of 29 September 1969.
  • Registers 6.5 on the Richter Scale.
  • Chaos in most places.
  • Rumbling grew louder and louder and was followed by tremendous quake.
  • The whole earth shuddered and people ran about panic stricken.
  • Rescuers used the Post Office as a base because it was the only place which had electricity.
  • Homes were badly damaged and people were badly injured.
  • Emergency aid streamed to the disaster towns and the police and army co-operated.
  • People were housed in tents and field hospitals were erected.
  • The water shortage was alleviated and food was supplied.
  • R13 million donated by the Disaster Committee

Assignment 3:

  • (sketch)

Assignment 4:

1. The Richter Scale is the instrument (scale) which seismologists use to measure the strength of an earthquake.

2. Seismologists are scientists who study earthquakes.

3. The place at which the shock waves first reach the surface of the earth is known as the epicentre.

4. If the pressure in the mantel under the crust builds up then magma is forced through weak places and cracks. These weak places then form volcanic pipes.

5. Active volcanoes are volcanoes which erupt from time to time.

Leaner section

Content

Activity: to analyse the structure of the earth and to measure movements in it (natural disasters) [lo 2.1, lo 2.3]

STRUCTURE OF THE EARTH

  • Scientists believe that Earth came into existence about 4 600 million years ago as a large cloud of gas and dust swirling around in space. While it was rotating it shrank to an extremely hot, liquid ball. The surface gradually cooled and a crust of solid rock formed which weathered to the mountains, soil and sand on which we live today.
  • Earth is continually changing. The land masses (continents) are not only moving, but new crust is forming all the time. The movement of the crust is called continental drift and it is still occurring. America, for example, is moving gradually away from Europe. This movement has already led to telephone cables under the Atlantic breaking.

FOUR LAYERS OF THE EARTH

  • The Crust

The crust is the outermost layer and has a thickness of from 5 km to 70 km. Under the oceans the crust can be as thin as 5 km and where there are mountains the crust can be as thick as 70 km. Beneath the crust there are three other layers. They are:

  • The Mantle

The mantle is 2 900 km thick. It is solid but contains slowly flowing currents of semi-melted metals.

  • The outer Core

The outer core consists of liquid metal and is responsible for the earth’s magnetic field. It is 2 240 km thick.

  • The inner Core

The inner core in the middle of the earth is probably solid and consists mainly of metals. The temperature is 3 700 degrees Celsius. Water boils at 100 degrees Celsius. The inner core has a diameter of 2 240 km.

The lava that flows from volcanoes comes from the mantle.

TASK 1: GROUP WORK

Use playing dough (four different colours) to make a model of Earth’s structure. The thickness of each layer should be more or less proportional to the actual thickness of the earth’s layer.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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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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