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“We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation.” ― Antoine Lavoisier, Elements of Chemistry

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Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

Tuesday, 1 December 2015

Pre Chemistry Semester 1 Final Exam for Checkpoint (grade 7 & 8)

Click the link below, 4shared.com will be opened in a new window. then click "unduh" or download. If your download does not automatically start, click google+ 

For CP1 (grade 7) :

Checkpoint 1(grade 7) - link 1 or  checkpoint 1 - link2

For CP2 (grade 8)

Checkpoint 2 (grade 8) - link 1    or checkpoint 2 - link2    

                               

Thursday, 19 November 2015

ONLINE IGCSE CHEMISTRY QUIZ: METAL EXTRACTIONS+Key Answer

Click the link below:

METAL EXTRACTION


Key Answer

Here is the key answer

Wednesday, 18 November 2015

QUIZ CP2

Click the link below:

ONLINE QUIZ CP2

Monday, 4 May 2015

Periodic Table Worksheet




1. Compare protons, neutrons and electrons


Protons
Neutrons
Electrons

Charge



Location in
Atom




2. Look at the figure below.       
       2

      He
     4.0

a.  What is the top number called? ______________
b.  What is the bottom number called? _____________

3. How do you find the number of protons?

4. How do you find the number of electrons?

5. How do you find the number of neutrons?

6. Complete the following:
                a.  Nitrogen                                                                       
                                Atomic Number   ____
                                Atomic Mass       ____
                                Protons               ____
                                Neutrons             ____
                                Electrons             ____
                b.  Sodium                                                                                          
                                Atomic Number   ____
                                Atomic Mass       ____
                                Protons               ____
                                Neutrons             ____
                                Electrons             ____
                               
7. How is the Periodic Table of the Elements organized?



8. Where are the metals, nonmetals and metalloids located on the Periodic Table?


9. If the statement is true write true. If the statement is false, change the underlined
word or words to make the statement true.

____________________ 1. The majority of elements in the periodic table are nonmetals.

____________________ 2. The reactivity of metals tends to increase as you move from left to right across the periodic table.
____________________ 3. Zinc, iron, nickel, and copper are examples of transition metals.

____________________ 4. The elements of Group 1 of the periodic table are called the lanthanides.

____________________ 5. Most metals are good conductors of electric current and heat. 


10. Name and configure the electrons of these following elements according to KLMN and spdf configuration.  Give the location/position of  the  element in the periodic table.

a)         20Ca
Name :
KLMN configuration :


Spdf configuration :

b)        54Xe
Name :
KLMN configuration :



Spdf configuration :


c)         46Pd
Name :
KLMN configuration :



Spdf configuration :



d)        64 Gd
Name :
KLMN configuration :



Spdf configuration :



e)        28Ni
Name :
KLMN configuration :





Spdf configuration :

Tuesday, 7 April 2015

Exercise for Checkpoint Cambridge Exam

Monday, 6 April 2015

CP1- Homework (Task2)

Periodic Table Worksheet-fill in the blank

Periodic Table Worksheet 1
Fill in the gaps by choosing the following words

 1      2      atomic      disimilar      dull      electronic      elements      equals      few      good      group      high      low      mass      metals      neon      non-metals      outer      period      poor      potassium      proton      shiny      similar      sodium      transition   

1. The chemical elements in the Periodic Table were originally arranged in order of their atomic ………………….

2. This list can then be arranged in rows so that elements with……………………………. properties are in the same vertical column, known as a………………………………………….

3. The horizontal row is called a…………………………….

4. In the modern periodic table elements are arranged in order of their atomic or…………………………………. number.

5. Argon is more like helium or ……………………………….. and not a bit like potassium.

6. Similarly potassium is more like lithium and ……………………………………. and so is better placed in Group ………………………………..  the "Alkali Metals"

7. The periodic table can also be seen as an arrangement of the elements in terms of their ……………………………….. structure.

8. Elements in the same group have the same number of …………………………………….. electrons.

9.  More than three-quarters of the elements of the periodic table are…………………………………….

10. They are mainly found in the left hand columns (Group 1 and Group………………………………) and in the central blocks of …………………………………. metals.

11. They tend to be ……………………………………. in appearance, ……………………………………. conductors of heat and electricity and the melting and boiling points and densities tend to be …………………………………

12. About one quarter of the elements are………………………………….. and these can be gases, liquids or solids.

13.  The solids tend to be …………………………….. in appearance and are ………………………….. conductors of heat and electricity. The boiling points and melting points and densities tend to be relatively…………………………...

source: docbrown

Thursday, 19 March 2015

Balancing Chemical Equations Worksheet

Balance these following chemical equations. show your working!

1.    ___Li2O  + ___H2O à ___LiOH
2.    ___CaC2  + ___H2O à ___C2H2  + ___Ca(OH)2
3.    ___Fe(OH)3 à ___Fe2O3  + ___H2O
4.    ___Pb(NO3)2  à ___PbO  + ___NO2  + ___O2
5.    ___BaO  + ___H2O à ___Ba(OH)2
6.    ___Ca  + ___AlCl3 à ___CaCl2  + ___Al
7.    ___NH3  + ___NO à ___N2  + ___H2O
8.    ___H3PO3 à ___H3PO4   + ___PH3
9.    ___Fe2O3   + ___C à ___CO  + ___Fe

10. ___FeS  + ___O2 à ___Fe2O3  + ___SO2

Saturday, 7 March 2015

Slides: Types of Chemical Reaction

click here to download the presentation slide

Types of Reaction Worksheet and Answer

Types of Chemical Reactions Worksheet

There are 5 major types of reactions simplified by the following equations:
  • Synthesis/Combination      A + B à AB
  • Decomposition                     AB à A + B
  • Combustion                          ? + O2 à ?
  • Single Replacement            X + AB à XB + A               or            Y + AB à AY + B
  • Double Replacement          XY + AB à XB + AY

Classify each of the following reactions:

1. Zn   +    Cl2  à ZnCl2                                 combination
2. 2 H2S +   3 O2 à   2 SO2  +    2 H2O         combustion
3. Cu + 2 AgNO3 à Cu(NO3)2 + 2 Ag          single replacement
4. Mg(OH)2 à MgO + H2O                           decomposition
5. CaCl2    +    Na2SO4 à CaSO4 + 2 NaCl   double replacement
6. CaO +    H2O à Ca(OH)2                                      combination  
7. Pb  + 4 HCl à PbCl4 + 2 H2                      single replacement
8. Li2O +   CO2 à LiCO3                               combination
9. SO2 +   H2O à H2SO3                               combination
10. MgCO3 à MgO + CO2                            decomposition
Predict the product and Classify each of the following reactions when only the reactants are given:

1. Mg  +  N2 à Mg3N2                                             combination
2. C2H6 +  O2 à CO2  +  H2O                                  combustion
3. Zn  + CuCl2  àZnCl2   +  Cu                               single replacement
4. Ca  + H2àCa(OH)2 + H2                                single replacement
5. AgNO3    +    NaI àAgI  + NaNO3                      double replacement
6. Fe(NO3)3    +    LiOH à Fe (OH)3 + LiNO3        double replacement
7. MgCO3 àMgO + CO2                                          decomposition
8. SO2 +    H2O àH2SO3                                          combination
9. HI àH2 + I2                                                          decomposition
10. H2SO4    +    LiOH à Li2SO4  +  H2O              double replacement
Convert these following into symbol equations
  1. Some grey magnesium ribbon was added to colourless dilute hydrochloric acid. The metal dissolves producing magnesium chloride and produces some hydrogen gas.

Mg(s)  +  HCl(aq)   à  MgCl2(aq)  +  H2(g)
  1. Some zinc metal is added to copper(11) sulphate solution. The zinc becomes coated with copper and colourless zinc sulphate solution is produced.

Zn(s)  +  CuSO4(aq)  à  ZnSO4(aq)  +  Cu(s)
  1. Some colourless hydrogen gas is mixed with colourless oxygen gas. The mixture is sparked and it explodes producing steam which condenses to liquid water.

H2(g)  +  O2(g)  à  H2O(l)
  1. Magnesium ribbon is burnt in carbon dioxide gas. It burns splattering as it goes. Black carbon is produced and some magnesium oxide solid.

Convert these word equations below into symbol symbol equations. Then classify the following reactions, represented by word equations, as synthesis/combination, decomposition , single replacement, double replacement, combustion
1)      sulphur + oxygen à  sulphur dioxide                                    ……………...

S  +  O2  à  SO2                               combination


2)      sodium + chlorine à  sodium chloride                                   ……………...

Na    +  Cl2   à   NaCl                      combination


3)      magnesium + oxygen à   magnesium oxide                          ……………...

Mg   +    O2    à    MgO                   combination/combustion


4)      magnesium + hydrochloric acid    ----------->  magnesium chloride + hydrogen ……………...
                                                         HEAT

Mg    +   HCl    à   MgCl2    +   H2 single replacement

5)      calcium carbonate ----------->.calcium oxide + carbon dioxide                                   ……………...
                                HEAT


CaCO3  à  CaO   +  CO2                decomposition

6)       mercury oxide      -------------->  mercury + oxygen                           ……………...
HEAT


            Hg2O  à  Hg  + O2                           decomposition


7)      sodium nitrate à sodium nitrite + oxygen                 ……………...

NaNO3  à  NaNO2  +  O2               decomposition



8)      aluminium + iron III oxide  -------------->aluminium oxide + iron ……………...
HEAT


            Al   +   Fe2O3   à  Al2O3   +  Fe     single replacement


9)      cobalt II chloride crystals --------------->.anhydrous cobalt chloride + water vapour                   
                                              HEAT                                                                 ……………...

CoCl2. n H2O  à   CoCl2   +   H2O           decompostion


10)  nitrogen + hydrogen ---------------> ammonia (hydrogen nitride) ……………...
                                  iron catalyst


            N2  +   H2   à  NH3                          combination

Friday, 6 March 2015

IGCSE Chemistry paper

Wednesday, 4 March 2015

Friday, 27 February 2015

Model Paper 3 for IGCSE Chemistry

Model paper 3.
click here to download

Thursday, 26 February 2015

Types of Chemical Reaction Worksheet


TOPIC : TYPES OF REACTION

Classify each of the following reactions:

1. Zn   +    Cl2  à ZnCl2
2. 2 H2S +   3 O2 à   2 SO2  +    2 H2O
3. Cu + 2 AgNO3 à Cu(NO3)2 + 2 Ag
4. Mg(OH)2 à MgO + H2O
5. CaCl2    +    Na2SO4 à CaSO4 + 2 NaCl
6. CaO +    H2O à Ca(OH)2
7. Pb  + 4 HCl à PbCl4 + 2 H2
8. Li2O +   CO2 à LiCO3
9. SO2 +   H2O à H2SO3
10. MgCO3 à MgO + CO2
Predict the products and classify each of the following reactions when only the reactants are given: 

1. Mg  +  N2 à
2. C2H6 +  O2 à
3. Zn  + CuCl2  à
4. Ca  + H2à
5. AgNO3    +    NaI à
6. Fe(NO3)3    +    LiOH à
7. MgCO3 à
8. SO2 +    H2O à
9. HI à

10. H2SO4    +    LiOH à