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Natuurwetenskappe

Graad 8

Materie: klassifikasie

Module 21

Verbindings en mengsels

VOORKENNIS

  • In die vorige deel van die werk het ons verduidelik wat ‘n element is en dat dit uit atome bestaan.
  • Ons het genoem dat atome nie geïsoleerd voorkom nie, maar verbind tot molekule.

Klasaktiwiteit: praktiese ondersoek

Ondersoek na fisiese eienskappe van elemente

Jou onderwyser sal hulp verleen in jou ondersoek na die individuele elemente yster en swawel se fisiese eienskappe en die veranderinge wat dit ondergaan wanneer dit verbind.

1. Hoe lyk die yster?

2. Hoe lyk die swawel?

3. Word die yster deur die magneet aangetrek?

4. Word die swawel deur die magneet aangetrek?

5. Wat kan jy hieruit aflei?

6. Voeg ‘n bietjie koolstofbisulfied (CS 2 ) by die yster.

Wat gebeur?

7. Voeg ‘n bietjie koolstofbisulfied (CS 2 ) by die swawel.

Wat gebeur?

8. Wat kan jy hieruit aflei?

Gooi die inhoud van die proefbuise nou uit in twee horlosieglaseen laat dit indamp.

9. Wat is sigbaar nadat die koolstofbisulfied verdamp het?

Ondersoek na fisiese eienskappe van mengsels

Voeg nou ystervylsels en swawel saam.

1. Hoe lyk die mengsel?

2. Wat gebeur, indien jy nou die magneet nader bring?

3. Wat kan jy hieruit aflei?

4. Voeg nou CS 2 by die mengsel. Wat gebeur?

5. Kan jy dus die mengsel skei?

6. Stel twee maniere van skeiding voor

Klasaktiwiteit (vervolg): demonstrasie

1. Wat gebeur as die yster en die swawel saam verhit word?

2. Het ‘n nuwe stof gevorm? Hoekom sê jy so?

3. Het die stof nog magnetiese eienskappe?

4. Is die stof oplosbaar in koolstofbisulfied?

5. Kan jy die stof weer terugskakel na die oorspronklike elemente?

6. Wat was nodig vir die reaksie om plaas te vind?

7. Watter energie-omsetting het plaasgevind?

8. Voltooi die volgende tabel van vergelyking:

MENGSELS VERBINDINGS
‘n Onsuiwer stof ‘n ......................................................... stof
Samestelling wissel Samestelling ......................................................
Geen energie betrokke by vorming Energie ..............................................................
Eienskappe van individuele stowwe word behou ............................................... eienskappe vorm
Kan geskei word met fisiese metodes, bv. magneet Kan slegs ...................................... geskei word

Assessering van eksperiment

Kon jy die stappe beplan (AS 1.1), uitvoer (AS 1.2) en jou bevindinge kommunikeer (AS 1.3)?

[LU 1.1; 1.2; 1.3]

Assessering

LU 1

Wetenskaplike Ondersoek

Die leerder is in staat om met selfvertroue op weetgierigheid oor natuurlike verskynsels te reageer, en om binne die konteks van wetenskap, tegnologie en die omgewing verbande te ondersoek en probleme op te los.

Dit is bewys as die leerder:

1.1 ondersoeke kan beplan;

1.2 ondersoeke kan uitvoer en data kan insamel;

1.3 data kan evalueer en bevindinge kan kummunikeer.

Memorandum

Verbindings en mengsels

KLASAKTIWITEIT: PRAKTIESE ONDERSOEK

ONDERSOEK NA FISIESE EIENSKAPPE VAN ELEMENTE

1. grys hard

2. geel poeier

3. ja

4. nee

5. metale is magneties

6. niks

7. swawel los op

8. metale onoplosbaar in koolstofbisulfied

9. kristalle – swawel

ONDERSOEK NA FISIESE EIENSKAPPE VAN MENGSELS

1. grys-geel

2. slegs ystervysels aangetrek

3. slegs metaal magneties

4. slegs swawel los op

5. ja

6. los S op en damp weer in – kristalle terug of magneet

KLASAKTIWITEIT: DEMONSTRASIE

1. versmelt tot nuwe stof

2. ja – lyk anders; eie eienskappe

3. nee

4. nee

5. ja met moeite

6. hitte

7. hitte- chemies

8. Voltooi die volgende tabel van vergelyking

MENGSELS VERBINDINGS
‘n Onsuiwer stof ‘n ……suiwer…….stof
samestelling wissel samestelling vasgestel………….
Geen energie betrokke by vorming energie………….benodig
Eienskappe van individuele stowwe word behou …nuwe…….eienskappe vorm
Kan geskei word met fisiese metodes bv. magneet Kan slegs …chemies en met moeite………..geskei word

Questions & Answers

it is the relatively stable flow of income
Chidubem Reply
what is circular flow of income
Divine Reply
branches of macroeconomics
SHEDRACK Reply
what is Flexible exchang rate?
poudel Reply
is gdp a reliable measurement of wealth
Atega Reply
introduction to econometrics
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Tom
Why is unemployment rate never zero at full employment?
Priyanka Reply
bcoz of existence of frictional unemployment in our economy.
Umashankar
what is flexible exchang rate?
poudel
due to existence of the pple with disabilities
Abdulraufu
the demand of a good rises, causing the demand for another good to fall
Rushawn Reply
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost 6% more than previous year? Provide with reasoning.
Geetha Reply
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Waeth
discus major problems of macroeconomics
Alii Reply
what is the problem of macroeconomics
Yoal
Economic growth Stable prices and low unemployment
Ephraim
explain inflationcause and itis degre
Miresa Reply
what is inflation
Getu
increase in general price levels
WEETO
Good day How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200. Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
Chisomo Reply
how to calculate actual output?
Chisomo
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Beshir
Criteria for determining money supply
Thapase Reply
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Muhammad
Aggregate demand
Mohammed
C=k100 +9y and i=k50.calculate the equilibrium level of output
Mercy Reply
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A unit of account is something that can be used to value goods and services and make calculations
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Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9 no Mpc is greater than 1 Y=100+.9Y+50 Y-.9Y=150 0.1Y/0.1=150/0.1 Y=1500
Kalombe
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Kalombe
hi can someone help me on this question If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output? discuss your answer using appropriate graph.
Galge Reply
if interest rate is increased this will will reduce the level of income shifting the curve to the left ◀️
Kalombe
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Source:  OpenStax, Natuurwetenskappe graad 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11049/1.1
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