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Natural sciences

Grade 8

Matter: classification

Module 15

Phase changes of matter

Prior Knowledge:

  • Matter has three phases: solid substances, liquid substances and gases

Class activity: reading skill

In the heart of a Cape winter

Adventurers went camping in the Cedar Mountains.

The night brought a fall of snow that

Glistened in the early morning light.

Slowly, surely, the ice was melted by the wintry sun

And water ran in rivulets to the riverbed.

A camper scooped up a billycan of the stream’s water

He struck a match to light his fire

And soon steam billowed from his billycan!

1. Name all the phases of water mentioned in the text – list all the descriptive words.

2. Name the source of energy that causes:

a. the ice to melt

b. the water to steam

3. a. In which phase do particles of water have the greatest freedom of movement?

b. Which phase presents the strongest attraction between particles of water?

4. The phases of water are also an important part of nature, as the WATER CYCLE becomes possible because of it. Fill in the following:

The Water Cycle

6. The following illustrations represent phase changes. Explain what happens to the water in each instance:

Assessment of reading skills

Were you able to make the correct deductions from the text?

[LO 2.3]

Assignment

Find out the following:

(You could use the given web addresses or any other source for research.)

Why ice floats on water.– www.geocities.com (iceberg+ float)

How snowflakes are formed.– google.com (snowflakes)– www.edu.pe.ca/rural/chemist

Why alcohol (as in Schnapps or Witblits) does not freeze in the freezer.

What the boiling point of fluids like cooking oil and alcohol is.– www.ucc.ie – (boiling points)

Paste or write the information on the facing page.

Assessment for assignment

Has the information been collected and recorded?

[LO 1.3]

7. Each substance has its own boiling and freezing point.

Water freezes at

Water boils at

 Do you know the following? 

A fourth phase of matter has been discovered – it is known as PLASMA.

It only occurs at excessively high temperatures and in stars.

Read more about PLASMA!

http://scsc.essortment.com

Assessment

Learning outcomes 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.

We know this when the learner

1.3 is able to evaluate data and communicate findings.

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

2.3 is able to interpret information.

Memorandum

1. snow; ice (solid substance) – water; river water (liquid) – steam (gas)

2. a) sun b) fire

3. a) steam (gas) b) snow/ice

4. spaces smaller in solid substances

5. 1 – evaporation; 2 – transpiration; 3 – cloud formation / condensation

4 – precipitation (rain, snow, etc.)

6. condenses; melts; freezes (crystallises); evaporates

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
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
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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
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
can nanotechnology change the direction of the face of the world
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
how did you get the value of 2000N.What calculations are needed to arrive at it
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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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