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Natural sciences

Grade 8

Matter: classification

Module 20

Metals and non-metals

  • A metal typically is a hard, shiny and strong element that is able to conduct heat and electricity.
  • Iron is the most commonly used metal in the world in which we live, though not in its pure form. When iron is combined with a small amount of a non-metal like carbon we obtain an alloy .
  • The study of metals is known as metallurgy .
  • Gold is generally regarded as a metal that symbolizes wealth and prosperity, while platinum and palladium are valuable because of their use in electronics and specialized engineering.
  • Steel is known everywhere and millions of tons of steel are used annually to manufacture items such as washing machines, cars, ships and trains. Stainless steel is also used for cutlery. For this, it is made into an alloy with the use of hard, shiny chromium .
  • A variety of substances can be added to iron to form alloys , e.g. manganese, phosphorus, silicon and sulphur.
  • Aluminium , again, is used extensively for cold drink cans, ladders and objects that are required to be light and rust free. Aluminium is the third most common chemical element on earth as much of the earth’s crust is made up of it. Copper and magnesium are usually added to aluminium to make it suitable for industrial use.
  • Metals can be recycled successfully to protect our natural resources – the gold and silver used in electrical circuits (and in false teeth!), particularly.
  • Bronze – a mixture of copper and tin - is one of the most ancient of alloys.
  • Brass is an alloy of copper and zinc.

Class activity

Recognition of metals and non-metals

  • Identify as many substances as possible from the illustration and classify them as metals and non-metals according to the main element of their substance.

1. Which feature did you consider to determine whether substances were metals or non-metals?

2. Do you think the secretary is prosperous? Provide a reason for your answer?

3. Which substance is taking over from this metal in industry? From what is it made?

4. What is metallurgy?

5. What is steel?

6. The following are the distinctive features of metal. Write down the distinctive features for non-metals:


hard and shiny

pliable and malleable

conducts heat

conducts electricity

7. What is the difference between pliable and malleable?

Assessment of recognition

Were you able to do the classification correctly and to apply your knowledge?

[LO 2.2; LO 2.4]


Learning outcomes 2: Constructing science knowledge

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

We know this when the learner

  • is able to categorise information;

2.4 is able to apply knowledge.




1. shiny, hard

2. gold

3. demand

4. study of metals

5. alloy


Hard and shiny - Different colours; not very hard

Pliable and malleable - Brittle, breaks

Conducts heat – No

Conducts electricity - NO

7. Pliable – long threads stretched out.

Malleable – hammered into thin plates/sheets.

Questions & Answers

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Differences Between Laspeyres and Paasche Indices
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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what is nanomaterials​ and their applications of sensors.
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what is nano technology
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what is system testing?
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
what is system testing
what is the application of nanotechnology?
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
anybody can imagine what will be happen after 100 years from now in nano tech world
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
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
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silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
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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
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
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Source:  OpenStax, Natural sciences grade 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
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