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Natuurwetenskappe

Graad 5

Materiaal

Module 28

Natuurlike materiale

Aktiwiteit:

Om die aard en gebruike van natuurlike materiale te bespreek

[lu 1.1; 1.2.1; 1.2.2; 1.3.1; 3.2]

1. Hout

Hout kom van bome wat dwarsoor die wêreld òf natuurlik groei, soos in woude, òf deur die mens in die vorm van plantasies aangeplant word.

Wanneer bome, veral in plantasies, volgroei is, word dit afgekap. Dun hout, soos takke en die stamme van swak bome, word verpulp om papier te maak. Dik stamme word na die saagmeule vervoer. Daar word dit in planke gesaag en gedroog. Droë hout word timmerhout genoem.

Hout kan vir baie dinge gebruik word, soos vir meubels, deure, kissies en speelgoed. Hout kan ook gebruik word om huise te bou. Musiekinstrumente soos die kitaar en viool word ook van hout gemaak. Die wiel van ‘n wa is ook destyds van hout gemaak.

Die verpulping van hout vir papier word in fabrieke gedoen. Die hout word met water en chemikalieë gemeng en in dun, gladde velle uitgerol en gedroog om as papier gebruik te word.

Ander gebruike van hout

Kyk na jou potlode of potloodkryte. Waarvan is dit gemaak?

Afvalplanke word dikwels in informele nedersettings gebruik om vinnig ‘n “huis” aanmekaar te slaan, aangesien dit darem skuiling bied.

In tropiese lande waar dit baie reën, word houthuise dikwels op pale gebou sodat die inwoners droog bly gedurende die reënseisoen en ook om ongewenste “gaste”, soos slange, uit te hou.

Indien hout goed versorg word, kan dit wisselende weersomstandighede weerstaan en huisbewoners teen koue of hitte beskerm.

Groepwerk

Maak ‘n plakkaat met die volgende inligting:

Hoe hout gebruik word in die boubedryf

OF

Produkte wat van hout gemaak is

Prente of sketse ter illustrasie sal in jul guns tel.

2. Keramiek en klei

Daar is volop klei in die kors van die aarde beskikbaar. Nie alle klei is op dieselfde manier saamgestel nie. Keramiek word gevorm deur klei wat gebak word. Verskillende soorte klei gee verskillende soorte keramiek.

Kyk watter voorwerpe van keramiek gemaak word.

Keramiek word as elektriese isoleerders gebruik – dit verhoed dat elektrisiteit in die staalstutte of -rame vloei.

Kom ons observeer hoe ‘n keramiekpot uit klei gemaak word:

1. Klei wat klam is, kan makliker in ‘n spesifieke vorm geskep word. So lyk die samestelling van nat klei:

2. Nadat ‘n kleipot gemaak is, word dit teen kamertemperatuur gelaat om stadig droog te word. Die deeltjies of molekules water in klei verdamp en die klei krimp en word hard.

So lyk die samestelling van die klei nou.

3. As die klei droog is, word dit in ‘n pottebakkersoond gebak (erdeware teen ± 980°C en steenware teen ongeveer 1 200°C tot 1 700°C).

So lyk die samestelling van die klei nou.

Nou is daar te min ruimte tussen die deeltjies klei of molekules om water deur te laat.

Opdrag 1:

Kyk na die keramiekpot met blomme en verduidelik die volgende:

  1. Hoe bly die blomme vars?
  1. Waarom lek die pot nie?
  1. Dink jy vloeistowwe kan in keramiekhouers gehou word?
  1. Noem ‘n paar voorbeelde waar keramiek daagliks gebruik word:
  1. Waarvoor het mense lank gelede klei gebruik?

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
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SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
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Cied
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Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
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Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
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Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
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
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
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Damian
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Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
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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, Natuurwetenskappe graad 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10980/1.2
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