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Natural sciences

The earth and beyond

Properties and uses of materials

Educator section

Memorandum

Assignment 6:

1. What is the colour of the crystal?

  • Purple

2. What happens to the coloured water around the crystal when the heating begins?

  • When the water is heated it rises.

3. What happens to the coloured water near the surface of the water?

  • The coloured water near the surface begins to move in a circle in the Pyrex dish. It sinks in the part that is not being warmed by the burner..

Assignment 7:

  • (Groupwork)
  • When a see breeze is caused by convection, your group should be able to work out how a land breeze occurs. Make sketches and write your explanation here.

How does a land breeze occur?

During the night the land cools more quickly than the sea. The sea stays warm longer than the land. The warm air above the sea rises. Cooler air from the land blows towards the sea

Assignment 8:

1. What happens when you place the pane of glass in front of the heater?

  • Immediately you feel less heat.
  • (The heater / source of heat is not warm enough. Glass obstructs radiated heat from the heater, just like wood or cardboard)

Assignment 9:

1. Does your hand immediately feel the heat?

  • Yes

2. How does the heat reach your hand?

  • Through radiation.

3. Does the glass of the bulb prevent radiance?

  • No, because the radiation from a very warm (white hot) object can penetrate glass.
  • Explanation: Water conducts electricity and if you touch an electrical appliance while you are standing on the ground the current flows through your body to the ground. This can cause a fatal shock.

Leaner section

Content

Activity: to discover the properties of materials [lo 1.2, lo 2.1, lo 2.3]

4. MATERIALS CAN TRANSFER HEAT

If you hold a teaspoon in boiling water it feels warm when you touch it. Heat has thus been transferred from the water to the teaspoon. (This transfer of heat will not happen if both substances are the same temperature.)

Transfer of heat takes place in three ways: Conduction, convection and radiation.

4.1 Conduction:

This is the transfer of heat from one part of a substance to another, while each part remains in its place.

  • Conduction takes place in solids.
  • Most metals are good conductors of heat.
  • Non-metals such as glass, wood, rubber, paper, plastic and asbestos are poor conductors of heat.
  • Solids do not all conduct heat equally well.

Interesting uses of poor conductors:

  • Handles of pans, irons, etc. are made of wood or plastic or other poor conductors. This keeps ones hand from getting burnt.
  • Clothes (wool, cotton), the furs of animals, feathers, are all poor conductors of heat.
  • A glass table top and table mats of wood, cork, cotton or plastic protect shiny wooden table tops from being marked by warm pots.
  • Cold meat and cold drink can be kept cold on a long journey by wrapping them in newspaper or a woollen blanket. Paper and wool are poor conductors.
  • Ice can be kept for a long time in sawdust or wrapped in a towel.
  • Houses with thatched roofs are warm on cold days and cool on hot days.
  • House with flat roofs are insulated with a layer of glass fibre above the ceiling.
  • Eskimos build houses of snow to protect themselves from the cold.

Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
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.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
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
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
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
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
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
what is the k.e before it land
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
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 6. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11079/1.1
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