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Natural sciences

The earth and beyond

Properties and uses of materials

Educator section


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


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


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

what is variations in raman spectra for nanomaterials
Jyoti Reply
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.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
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
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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