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Natural sciences

Grade 8

Matter: classification

Module 21

Compounds and mixtures

Prior Knowledge

  • In the previous section of the work we learnt what elements are and that they consist of atoms.
  • We mentioned that atoms do not occur in isolation, but are combined in molecules.

Class activity: practical investigation

Investigation of physical qualities of elements

Your educator will help you to investigate the physical features of individual elements and the changes that occur when they combine.

1. Describe the iron filings:

2. Describe the sulphur:

3. Is the iron attracted by the magnet?

4. Is the sulphur attracted by the magnet?

5. What do you deduce from this?

6. Add a little carbon bisulphide (CS 2 ) to the iron.

What happens?

7. Add a little carbon bisulphide (CS 2 ) to the sulphur.

What happens?

8. What do you deduce from this?

Pour the contents of the test tubes into two watch-glasses.

9. What do you see when the carbon bisulphide has evaporated?

Investigation of physical qualities of mixtures

Add iron filings to the sulphur:

1. What does the mixture look like?

2. What happens when the magnet is brought closer to the mixture?

3. What can you deduce from this?

4. Now add CS 2 to the mixture. What happens?

5. Can you separate the mixture?

6. Suggest two methods of separation

Class activity (continued): demonstration

1. what happens when iron and sulphur are heated together?

2. Is a new substance formed? Explain your answer?

3. Has the substance retained any magnetic qualities?

4. Is this substance soluble in carbon bisulphide?

5. Can the substance be reconverted to the original elements?

6. What was required for the reaction to occur?

7. What kind of transfer of energy took place?

:

Assessment of experiment

Were you able to plan the steps (AS 1.1), execute them (AS 1.2) and communicate your findings (AS 1.3)?

[LO 1.1; LO 1.2; LO 1.3]

Assessment

Learning outcome 1: Scientific investigations

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

ASSESSMENT STANDARD: We know this when the learner

1.1 is able to plan investigations;

1.2 is able to execute an investigation and collect data;

  • is able to evaluate data and communicate findings

Memorandum

INVESTIGATION INTO PHYSICAL QUALITIES OF ELEMENTS

1. grey, hard

2. yellow powder

3. yes

4. no

5. Metals are magnetic.

6. nothing

7. sulphur dissolves

8. Metals do not dissolve in carbon bisulphide.

9. crystals – sulphur

INVESTIGATION INTO PHYSICAL QUALITIES OF MIXTURES

1. yellow-grey

2. Only iron filings are attracted.

3. Only metal is magnetic.

4. Only sulphur dissolves.

5. yes

6. Dissolves S and evaporates again – crystals back on magnet.

CLASS ACTIVITY: DEMONSTRATION

1. Fused into a new substance.

2. yes – looks different; own qualities

3. no

4. no

5. yes, with effort

6. heat

7. heat – chemicals

8. Complete the following comparative table.

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.
Damian
yes that's correct
Professor
I think
Professor
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
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
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
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 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 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
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