c04as Periodic Table of Elements PDF August 17 2011-5-48 Am 687k

8/14/2019 c04as Periodic Table of Elements PDF August 17 2011-5-48 Am 687k

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OOKKUSSMM NNUJUUGG MMILLNNGG

2009 Perak P2A1

ANSWER SCHEME

CHAPTER 4

PERIODIC

T LE

OF

ELEMENTS

JJKKDD KKIIMM IIAA KKLLUUAANN GG,, JJOO HHOO RR DDAARRUULL TTAAZZIIMM

01 : Introduction to Chemistry

02 : Structure of Atom03 : Chemical Formulae & Equations04 : Periodic Table of Elements05 : Chemical Bonds06 : Electrochemistry07 : Acids & Bases08 : Salts09 : Chemical Substances in Industry10 : Rate of Reactions11 : Carbon Compounds12 : Oxidation & Reduction13 : Thermochemistry14 : Chemicals for Consumers


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2007 Malacca P2A2

No. of Q Explanation Marks Total Mark

1 (a) 2.8.8 1 1

(b) W have achieve stable electron arrangement (octet) 1 1

(c) (i)

(ii)

S

increasing nuclei attraction on the valence electron

1 1

(d) (i)

(ii)

burn rapidly in oxygen to produce white solid metaloxides

4X + O 2 2X2O

1

1

1

1

(e) (i) X is more reactive than S 1 1

(ii) because X is located below than S, whwn going downthe group 1, reactivity increase

1 1

Total 10

2007 Pahang P2A2No Explanation Mark 2 (a) 2.8.2 1

(b)(i)

Ionic bond 1

(ii) Atom A releases 2 electrons to atom B- to achieve octet electron arrangement / to form ion A 2+.

11

(iii) Each ion drawn correctly 1+1(iv) Has high melting and boiling point 1(c)(i)

CB2 1

(ii) 12 + 2(32) / 12 + 64= 76

11

Total 10


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[email protected] 3

2008 Perlis P2A3


3(a) Proton, electron, neutron 1 1

(b) (i)

(ii)

The number of shells occupied with electrons

Period 3W has 3 shells occupied with electrons

1

11

1

2

(c) (i)

(ii)

Atomic size of atom X is smaller

-Proton number of atom X is larger - attraction of nucleus on the electrons in Period 2increases

1

1

1

1

2

(d) (i)

(ii)

ZX

Z+ 2.8 Y - 2.8.8

- No of electrons and shells are correct- The presence of charges

1

11

1

2

Total 10

2008 Kedah P2A4


4

(a) 1 1

(b) (i)

(ii)

Isotopes are atoms (of the same element) with thesame number of protons/proton number but differentnumber of neutrons/nucleon number

1 1

(c) (i)

(ii)

Any example of isotopeSample answer; carbon-14, cobalt-60, sodium-24 etc

1 1

(c) (i)

(ii)

12

23

Y11

1

1

1

1

(d) (i) Liquid 1 1


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(ii) 1 1

(iii) Becomes faster/ more active 1 1

(iv)

Time / min

Total 10

2008 Johore P2A3

No. of Q Explanation Marks Total

Mark

5 (a) (i) Group 1 and Period 4 1+1

2(ii) G

1 1

(b) (i) D 2L 1 1

(ii) Soluble in water// high melting / boiling point// conductselectricity in molten or aqueous solution

1 1

(c) (i) E 1 1

(ii) The nuclei attraction towards the valence electrons is weaker in E.

Thus it is easier for E to lose / release an electron to form a positively charged ion.

1

1

2

(d) (i) L//M 1 1

(ii) Covalent bond 1 1

Total 10

Temperature/ 0C


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[email protected] 5

2008 Perak P2A1

No. of Q Explanation Marks TotalMark

6 (a) increasing order of proton number 1+12

(b) (i) (i) Sodium / Na 1 1

(ii) Chlorine /Cl 1 1

(iii) advertising light / television tubes

(c) (i) Ionic 1 1

(ii) 11

2

(d) (i) Copper/ Cu 1 1

(ii) Formed a coloured compound // Act as catalyst // Formed acomplex ion // Have a various oxidation number

1 1

Total 10


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[email protected] 6

2009 Malacca P2A2


7

(a)(i)

(ii)

Group

period

1+12

(b) G 1 1

(c) B 1 1

(d) (i) Red litmus paper turns to blue 1 1

(ii) 1-correct chemical formula for reactant2-correct chemical formula for product3-balance the equation

2D + H 2O 2DOH + H 2 //2 Na + H 2O 2Na OH + H 2

2 2

(e) B,A,G,E,D,H 1 1

(f) (i) shade all transition element(ii) 1-show different oxidation number

2- form coloured ions/ compounds3-their element/compound used as catalyst

11

11

Total 10


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[email protected] 7

2009 Kelantan P2A1


8

(a) Group 16 ,period 3 1+1 2

(b) 2D +H 2O DOH + H 2Correct reactant and correct productBalance equation

11

2

(c) (i)

(ii)

G

The nuclei attraction towards the valence electron isweaker in G. Thus it is easier for G to lose / release anelectron to form a positive charged ion

1

11

3

(d) (i)

(ii)

F

Has stable //octet electron arrangement// have 8electron valence

1

1

2

(e) Show coloured ion//formed complex ion//has variousoxidation number//act as catalyst

1 1

Total 10


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[email protected] 8

2009 Sabah P2A1


9

(a) U and X 1 1

(b) Group 1 and period 4 1 1

(c) NeonUsed to fill advertising light bulb// use as an indicator light

11 2

(d) (i)(ii)

U2U + H 2O 2 UOH + H 2 //2X + H 2O 2XOH + H 2

11

2

(e) X. Its valence electrons can released more easilycompared to element U, because atom X is size is larger than atom U

2 2

(f) A valence electron at the outermost shell of atom U istransferred to atom W to achieved stable octet electronarrangement

11

2

Total 10


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[email protected] 10

2010 Pahang P2A3

No. Mark Scheme SubMark

TotalMark

11 (a) P 1 1(b) R 1 1(c) (i)

(ii)

The electronegativity is increase from Q to V

Across the period from Q to V , the atomic size decreases,The attraction force between nucleus and valens electronsincreases

1

1

1

3

(d) R is more reactive than Q 1 1(e) Because the element has octet electron arrangement/

Because the outermost shell has occupied 8 electrons.1 1

(f) (i)

(ii)

TU 4

Corect diagram, label T and U, correct no. of electronCorrect valens electron each of the atom

1

11

3

TOTAL 10 M


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2010 MRSM P2A2NO EXPLANATION MARK T MARKS

12

(a) (i) P and R 1

3

(ii) Both atoms have same number of protons but differentnumber of neutrons // Both atoms have same proton number but different nucleon number

1

(iii)

1

(b) (i) X 1

6

(ii) hydrogen gas

(iii) Colourless solution turns pink The reaction produces alkaline solution a: presence of OH-

11

(iv)2 Na + 2H 2O 2NaOH + H 2 1

(v) density of Group 1 metals are lower than the density of water // less dense than water

1

TOTAL 9


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2010 Pulau Pinang P2A1


13 (a)(i)

(ii)

E and F

increase

11 2

(b)(i)

(ii)

atom of the same elemnt with the same number of protons butdifferent number of neutrons

T study / estimate the age of fossil /artefacts

1

1

2

(c)(i)(ii)

Datom D has stable / octet electron arrangement

1 1

(d) (i) A/E 1 1

(ii) 2A + H 2O 2AOH+ H 2 //H2 + 2H2O 2EOH +H 2

2 2

(e) 2.8.7 1 1

(f) G 1 1

Total 10


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2010 Melaka P2A2


14

(a) (i) Group 13, Period 3 1+12

(ii) J and L1 1

(b) (i) Burns with yellow flame // produces hiss sound 1 1

(ii) 2L + 2H 2O 2 LOH + H 2 1 1

(c) (i) M 1 1

(d) (i) Covalent bond 1 1

(ii) [1. correct number of occupied electron shells and correct

electronsin each shell for all the atoms, nuclei shown ]

[2. four atoms of N combine covalently (sharing a pair of electrons) with one atom of K ]

1 1

Total 10


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2008 Sarawak P2C7


15 (a) (i)

(ii)

(b)

1. The electron arrangement of atom Q .2.1 // 2J 2. The electron arrangement of atom R : 2.4 // 2,4

1. The number of neutrons in atom R is 62. Symbol for Isotope of R : 6

13 R // 6 14R

1. Element Q and R forms covalent bond.2. Atom Q has an electron arrangement of 2.8.7 / 2,8,73. Atom R has an electron arrangement of 2.4 / 2, 4.4. To achieve the stable octet electron arrangement, atom R shares

electrons with atom Q.5. One atom R contributes 4 electrons.6. Each atom Q contributes one electron.7. Atom R shares four of its valence electrons each with 4

atoms of Q to form a covalent compound / molecule with theformula RQ4.

OR

11

11

1111

11

1

1

2

2

8

(c) For Group 1 elements,

1. Going down the group, atomic size increases //the valence electron becomes further away from the 1


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No. of Q Explanation Marks TotalMark nucleus.

2. Forces of attraction between the protons / nucleus andthe valence electron becomes weaker.

( Reject: electron shell.)

3. It is easier for the atom to donate / release the valenceelectrons.

4. Reactivity increases down the group //

For Group 17 elements,

5. Atomic size increases when descending the group // thevalence electrons becomes further away from the nucleus.

6. Forces of attraction between the protons / nucleus and thevalence electrons become weaker.

7. It is more difficult for the atom to accept / gain / receiveelectrons.

8. Reactivity decreases down the group //

1

1

1

1

1

1

1

8

Total 20


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2009 Kedah P2B7


16 (a) Electron arrangement of atom X is 2.8.2Atom X has two valence electrons

Hence, it is located in Group 2Atom X has three occupied shells//three shells filled with electronsHence, it is located in Period 3

11

111 5

(b) Electron arrangement of lithium 2.1Atomic radius of lithium is smaller than sodium//atomic size of lithium smaller than sodiumThe distance between the nucleus of lithium and the valenceelectrons is shorter /nearer/closer The force of attraction between the nucleus of lithium and thevalence electron is stronger Hence, the valence electron is more difficult to be released

11

1

1

1 5

(c) Procedure1-A small piece of lithium is cut using a knife2-The oil on the surface of lithium is removed using filter paper 3-Lithium is then placed slowly on the surface of water in a beaker/basin4-The experiment is repeated using sodiumObservationLithium moves slowly on the surface of water Name of products: lithium hydroxide and hydrogenSodium moves rapidly/faster/vigorously on the surface of water

Name of products: sodium hydroxide and hydrogenEquations2Li + 2H

2O 2LiOH + H

2correct formulae

balanced equationor 2Na + 2H

2O 2NaOH + H

2

11

11

111

1

11

10

Total 20


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2008 Kedah P2B8


17

(a) (i) Atom R is located in Group 17, Period 3 11

(ii) Electron arrangement of atom R is 2.8.7.It is located in Group 17 because it has seven valenceelectron.

It is in Period 3 because it has three shells filled

11

1 5

(b) Atoms P and R form covalent bond.To achieve the stable electron arrangement,atom P needs 4 electrons while atom R needs one electron.Thus, atom P shares 4 pairs of electrons with 4 atoms of R forming a molecule with the formula PR 4// diagram

1111

1

5

(c) Atom Q and atom R form ionic bondAtom Q has the electron arrangement 2.8.1. andAtom R has the electron arrangement 2.8.7.To achieve a stable (octet )electron arrangementatom Q donates 1 electron to form a positive ion// equation

Q .Q+ + e

111111

(d) (i) Atom R receives an electron to form ion R-/equationAnd achieve a stable octet electron // equationR - + e R

111

P

R

R

R

R


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Ion Q + and ion R are pulled together by the strongelectrostatic forces to form a compound with the formula QR 1

111

The ionic compound/ (b)(ii) dissolves in water while the covalent compound / (b)(i)does not dissolve inwater. Water is a polar solvent that can cause the ioniccompound to dissociate into ions.Covalent compounds are non-polar and can only dissolve inorganic solvents.

OR

The melting point of the ionic compound/ (b)(ii) is higher than that of the covalent compound/ (b)(i) .

This is because in ionic compounds ions are held by strongelectrostatic forces.High energy is needed to overcome these forces.

In covalent compounds, molecules are held by weak intermolecular forces.Only a little energy is required to overcome the attractiveforces.

OR

The ionic compound/(b)(ii) conducts electricity in the molten

or aqueous statewhereas the covalent compound/(b)(i) does not conductelectricity.This is because in the molten or aqueous state, ioniccompounds consist of freely moving ions.Covalent compounds are made up of molecules only

111

1

111

1

11111

max4/5

Total 20


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2009 Times P2B8


18 (a) - Atom U is smaller in size than atom T- Atom U has more protons in the nucleus

- Attractive forces between the nucleus and the electrons inthe shells are stronger.- Therefore,the electron lled shells are attracted closer to

the nucleus.

11

1

1 4

(b) - T is more reactive .- The electron arrangement of T is 2.8.1 and S is 2.1- The valence electron of atom T is further from its nucleus.- The attractive forces between the nucleus of atom T towards

the nucleus of atom T towards the valence electron is weaker - Therefore the tendency of atom T to donate the valence

electron is higher.

1111

1 5

(c)

Procedure:

1. A spatula of iron lings is put into the combustion tube.2. Gas U is passed over the hot iron lings.3. The iron lings are heated very strongly.

Observation:

- The iron lings glow brightly and a brown solid is formed.

Chemical equation:

2Fe + 3 U2 2FeU 3

1

111

1

1 6

(c) - S has the electron arrangement of 2.1.- S is located in Group 1- because S has 1 valence electron.- S is located in Period 2.- because S has 2 electron lled shells.

11111

11111

Total 10


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2010 Melaka P2B8


19(a) 1. Atomic radius increase as

2. more number of shells is needed to fill the increasing number

of electrons present in the atom3. melting point increase down the group4.atomic size increase down the group5. attraction forces between atoms become stronger 6. more heat is needed to overcome this stronger forces of attraction

11

1111

6

(ii) 1. Helium gas used to fill airship / weather/ fill up the diversoxygen tank 2. neonused in advertising lights3. Argon- used to fill up the light bulb4. krypton- used in lasers to repair retina of the eyes

1

111

4

(b)

(i)

(ii)

1. The valence electron in a group 18 atoms are stable/ (dupletand octet) while in group 17, the atom have 7 valence electrons.2.In order to achieve stable electron arrangement,each atom ingroup 17 elements need to share its valence electron with other element

3. For group 18 elements, the atom need not have to share their valence electron1- the reactivity decreases2- in chemical reaction, halogen atom needs to gain oneelectron (into their outermost shell).3.The atomic size of halogen increases down the group // the

outermost occupied shell of each atom becomes further fromnucleus.4.The strength of nucleus to attract electron becomes weaker

1

1

1

11

1

1

7

(iii) 1-ionic bond2- [ correct number of occupied electron shell,correct electronsin each shell and nuclei shown for both ions]3-one sodium ions combines with one chloride ion, correctcharges of ion written]

11

13

Total 20


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2010 MRSM P2 C9 NO EXPLANATION MARK E MARKS

20

(a)

2Na + Cl 2 2NaCl Number of mole of Na = 23 = 0.1 mol

1

11

4

23

2 mol of Na produce 2 mol of NaC10.1 mol of Na produce 0.1 mol of NaC1Mass of NaCI = 0.1 [23 + 35.5] 5.85 g

(b) `

(1) 2 Fe + 3C1 2 4 2FeC1 3 or 2 Fe + 313r 2 4 2FeBr 31. Correct formulae of reactants and products2. Balanced equation

1 2

(ii) 1. The reactivity of reaction I is higher than reaction II.2. The atomic size of chlorine is smaller than bromine3. The forces of attraction of the nucleus toward theelectrons is stronger in chlorine atom than in bromine atom4. It is easier for chlorine atom to attract electron

1 11 1 4

TOTAL 10


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2008 Johore P3DEQ No. Rubric / Sample answers Score21 (i) Able to give the problem statement accurately.

Sample answer: How does the reactivity of lithium, sodium and potassiumchange when they react with water?// How does the reactivity of Group 1

metals change when they react with water?

2

Able to give the problem statement correctly.

How does the reactivity of the three elements change with water?

1

No response or wrong response 0

Q No. Rubric / Sample answers Score(ii) Able to state the three variables correctly.

Sample answer:Manipulated Variable : Different types of alkali metals//Li, Na, K

Responding Variable : Reactivity of metals // the movement of metals onwater surfaceFixed Variables : Water, size of metals

3

Able to state any two variables correctly. 2 Able to state any one variable correctly. 1 No response or wrong response 0

Q No. Rubric / Sample answers Score(iii) Able to state the hypothesis correctly.

Sample answer:Potassium is more reactive than sodium & lithium //The reactivity increases when going down the Group 1.

3

Able to state the hypothesis less correctly.

Sample answer:-Different types of alkali metals, different reactivity of metals -Reactivity of metal depends on different types of alkalimetals

2

Able to state any idea of the hypothesis.

Sample answer:Reactivity of metal depends on the metal. //Potassium is the most reactive metal

1


Q No. Rubric / Sample answers Score(iv) Able to list all materials and apparatus accurately.

Sample answer:Material : lithium, sodium and potassium, Water and

3


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Filter paper Apparatus : Small knife, forceps, basin Able to list at least 3 materials and 1 apparatus correctly. 2 Able to list at least 2 materials and 1 apparatus correctly. 1 No response or wrong response 0

Q No. Rubric / Sample answers Score(v) Able to list all the procedures accurately.

Sample answer:1. Cut a small piece of lithium using a knife and forceps.2. Dry the oil on the surface of the lithium with filter paper 3. Place the lithium slowly onto the water surface in a trough using forceps4. Record your observations in the table5. Repeat steps 1-4 using sodium and potassium.

3

Able to list steps 1, 3 and 4 correctly. 2 Able to list steps 3 and 4 correctly.

1 No response or wrong response 0

Q No. Rubric / Sample answers Score(vi) Able to construct a table to tabulate the data that includes the heading for the

manipulated variable and the observations.

Sample answer:Elements Observation

Lithium

SodiumPotassium

3

Able to construct a table to tabulate the data that contain the elements or theobservation.

Elements Observation

2

Able to construct any table to tabulate the data.

Sample answer:LithiumSodiumPotassium

1


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2008 Pahang P3DEQ No. Rubric / Sample answers Score22 (a) Able to give the accurate problem statement. Response is in the question form.

(ignore the question mark)

Sample answer :How does the reactivity of group I elements/(alkali metals)(/metals X, Y and Z )change when react with water?

3

Able to give the accurate problem statement.Response is in the question form.(ignore the question mark)

Sample answer :How does the reactivity of group I elements/(alkali metals)(/metals X, Y and Z )change when react with water?

2

Able to give the idea of problem statement

Sample answerReactivity change// React with water [Able to state the idea of ]

1

No response given / wrong response 0

(b) Able to give all three variables accurately and correctly .

Sample answer :Manipulated variables: different types of metals

Responding variables: reactivityConstant variables : size of metals

3

Able to give any two variables correctly 2 Able to give any one variables correctly 1 No response given / wrong response 0

(c) Able to state the relationship between the manipulated variable and responding variable and the direction accurately

Sample answer :

When going down Group I, metals X,Y and Z becomes more reactive in their reactions with water

3

Able to state the relationship between the manipulated variable and responding variable

Sample answerWhen going down Group I ,the reaction of metals X,Y and Z with water becomes more reactive// Group I metals react with water vigorously

2

hypothesisSample answer

( Metals )reactive//react vigorously

1



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(d) Able to give all three variables accurately and correctly .

Sample answer :Manipulated variables: different types of metalsResponding variables: reactivity

Constant variables : size of metals

3

Able to give any two variables correctly 2 Able to give any one variables correctly 1 No response given / wrong response 0

(e) Able to write all the procedures correctly

Sample answer :1. Cut a small piece of metal X using a knife and a forceps

2. Dry the oil using filter paper 3. Place metal X slowly onto water surface in a trough4. Record your observations5.Repeat using metals Y

and Z

3

Able to write adequate procedures

Sample answer :Steps 1, steps 3 and steps 4

2

Able to write minimum procedures

Sample answer :Steps 1 and steps 3//Steps 3 only

1


(f) Able to exhibit the tabulation of data that includes the following four information:

1. heading for the manipulated

2. all metals3. heading for the responding variables4. 2 x 4 / 4 x 2 tables

Sample answer :metals Observation/reactivityXYZ

3


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Able to exhibit the tabulation of data that includes the following information:1. Heading for the manipulated and responding variables2. 2 metals

Sample answer

elements observationXY

2

Able to exhibit the tabulation of data that includes the following information1. heading for the manipulated/responding variable2. 1 metal

Sample answer

Material/substance

X

1



27/46


2008 Kedah P3A2Question Explanation Maximum

score

23

(a)

[Able to write the problem statement of the experiment accurately]

Sample answer:How do lithium, sodium and potassium differ in reactivity withwater?

3

[Able to write the problem statement of the experiment correctly]

Sample answer:How do lithium, sodium and potassium differ in reactivity?

2

[Able to write a relevant idea about the problem statement of theexperiment//Able to write aim of experiment accurately]

Sample answer:How do lithium, sodium and potassium differ?//To compare thereactivity of lithium, sodium and potassium when react with water.

1

[No response given or wrong response] 0

Question Explanation Maximumscore

(b) [Able to state the hypothesis

accurately] Suggested answers:

The reactivity of lithium, sodium and potassium towards water increases down the group

// The reactivity of lithium, sodium and potassium towardswater increases down the group

// The reactivity of lithium, sodium and potassium towards water in increasing order is :

Lithium, sodium and potassium

3

[Able to the hypothesis of the experiment]

The reactivity of lithium, sodium and potassium are different.

/ The reactivity of lithium, sodium and potassium towardsoxygen/ halogen increases down the group

2

[Able to state that there is a reaction between lithium sodium / potassium and water]

1



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MOZ@C


(c) [Able to state the three variables correctly]

Sample answer:Manipulated variable : Type of metal

Responding variables : Reactivity of

metal Fixed variables : Size of metal,

3

[Able to state any two variables correctly.] 2[Able to state only one variables correctly] 1[No response given or wrong response] 0


(d) [Able to state complete materials and apparatus]

Sample answer:Materials: Lithium, sodium, potassium, water Apparatus: Basin/beaker, filter paper, pen knife/blade, forcep/tongs

3

Able to state an six materials and a aratus correctl . 2[Able to state any three materials and apparatus correctly] 1



(e) [Able to write the complete procedure of the experiment

correctly] Suggested answer:

1. A small piece of lithium is cut using a knife and a pair of forceps

2. The surface of lithium is dried with filter paper

3. The piece of lithium is placed on the surface of water in a trough

4. The movement of lithium and any sound/flame given out isobserved and recorded

5 Re eat the ex eriment usin a small iece of sodium and

3

[Able to write the necessary steps of the expeimental

rocedure] Steps 1, 3, 4 and 52

[Able to write the minimum experimental

rocedure] Steps 3 and 51



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(f) [Able to

Sample

answer:

construct a labeled tabulation of data ]

3Metal Observation

LithiumSodium

Potassium[Able to

Sample

answer:

construct a tabulation of data ]

2Metal Observation

[Able toconstruct

a table consisting of two rows and two columns.]

1



30/46

2008 SBP P3DE

24 (a) KK0510 - State variables

EXPLANATION SCORE

[Able to state the three variables correctly]

Manipulated variable Type of elements/metals

Responding variable: Rate of reaction//Reactivity of the reaction

Fixed variable: Water, size of metal used

3

[Able to state any two variables correctly] 2

[Able to state any one variable correctly] 1


2 (b) KK051202 Stating hypothesis

EXPLANATION SCORE

[Able to state the relationship between manipulated variable and responding

variable correctly]

Suggested answer:

The metal which is below in Group 1 is more reactive the reaction withwater//The lower the metal in Group 1 the more reactive the reaction with

water

3

[Able to state the relationship between manipulated variable and

responding variablebut in the opposite direction]

Suggested answer:

The more reactive the reaction, the lower the position of the metal in Group 1

2

[Able to state an idea of the hypothesis]

Suggested answer:

Metals in Group 1 can react with water

1



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(c) KK0509 Operational definition

EXPLANATION SCORE

[Able to state the operational definition accurrately]

Suggested answer:

The metal that reacts more vigorously with water is a more reactive metal

3

[Able to give the operational definition correctly but inaccurrate]

Suggested answer:

The metals can react with water at a different rate.

2

[Able to state an idea of the operational definition]

Suggested answer:Metals can react with water.

1


(d) KK0504 Making inference

EXPLANATION SCORE

[Able to state the inference accurately]

Suggested answer:

The solution produced is a strong alkali.

3

[Able to state the inference correctly]

Suggested answer:

The solution produced is an alkali.

2

[Able to give idea for inference]

The metals dissolve in water.

1



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(e) KK0507- Making relationship

EXPLANATION SCORE

[Able to state the relationship accurrately]

Suggested answer:

The lower the position of the metal in Group 1, the higher the reactivity of the

metal towards water.

3

[Able to state the relationship correctly but less accurrate]

Suggested answer:

The reactivity of the metals is inversely proportional to their position in the

group.

2

[Able to state an idea of a relationship]

Suggested answer:

Position of metals affect the reactivity

1


(f) KK 0508 Interpreting Data

EXPLANATION SCORE

[Able to arrange the metals in descending order based on their reactivity]

Rb, K, Na, Li

3

[Able to arrange the metals in ascending order based on their reactivity]

Li, Na, K, Rb

2

[Able to arrange the position of at least three metals in descending order

based on ther reactivity]

1



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2009 Johore P3ES

Question No. Rubric Score

25 (a) Able to state the inference correctly.

Sample answer:

The reactivity (of alkali metals with oxygen) increase fromlithium to potassium. //

Lithium, sodium and potassium / alkali metals show similar chemical in their reactions with oxygen.

3

Able to state the inference less correctly.

Sample answer:

The reactivity increase //

All metals burns produced white fume and white solid //

Going down group I the reactivity increase.

2

Able to state any idea of inference.

Sample answer:

Lithium, sodium and potassium show different reactivity //

Potassium, Sodium, lithium

Increase

1



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Question No. Rubric Score1 (b) Able to state the three variables correctly:

1. Method to manipulate variable.2. The responding variable.3. The controlled variable .

Sample answer:

(i) Use different types of (alkali)/(group 1) metals

(ii) Reactivity of metals with oxygen //

Vigorousness of the reaction between metals andoxygen.

(iii) Oxygen gas // size / mass of metal

3

Able to state any two variables correctly: 2

Able to state any one variable correctly.1

No response or wrong response0

Question No. Rubric Score1 (c) Able to state the relationship correctly between the

manipulated variable and the responding variable.

Sample answer:(The lower/higher the position of metal in)/(Going down/up)Group 1, the more/less reactive is the metal in reaction withoxygen. //

The lower/higher the position of metals in group 1, thelower/higher is the reactivity.

The metal which is lower / upper in Group 1 is more/lessreactive in reaction with oxygen. //

The lower/higher the metal in Group 1 the more/less reactivethe reaction with oxygen.

3


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Able to state the relationship between the manipulated variable and the responding variable.

Sample answer:Reactivity increases for the reaction between alkali metalsand oxygen when going down Group 1/ from lithium to potassium. //

(The lower/higher the position of metal in)/(Going down/up)Group 1, the more/less reactive. //

The metal which is lower/upper in Group 1 is more/lessreactive //

The lower/higher the metal in Group 1 the more/less reactivethe reaction. //

The more reactive the reaction, the lower the position of themetal in Group 1.

2

Able to state the idea of hypothesis.

Sample Answer:Metals in Group 1 can react with oxygen. //

Alkali metals have different reactivity.

1

No response or wrong response

0

Question No. Rubric Score1 (d) Able to give the operational definition accurately by stating

the following three information.

- alkali metals- vigorously / more vigorous / reactive with oxygen- more / highly reactive

Sample answer:

An alkali metal that reacts more vigorously with oxygen is amore reactive metal.

3


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Able to give the operational definition correctly by stating any two of the information above.

Sample answer:

The metal that reacts more vigorously with oxygen is a morereactive metal. //

The alkali metal that reacts more vigorously is a morereactive metal. //

The higher/lower the alkali metals, the more/less reactivemetal.

2

Able to give the operational definition correctly by stating any one of the information above.

Sample answer:

Alkali metals can react with oxygen. //

Metals can react vigorously with oxygen.

1


Question No. Rubric Score1 (e)(i) Able to state the position of metal X in Group 1 accurately.

Sample answer:

Period 5/6/7

3

Able to make a prediction of the position of metal X in Group1 less accurately.

Sample answer:

Below /under potassium //Lower than potassium

2

Able to make any prediction of the position of metal X inGroup 1. 1


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Sample answer:

In group 1 // Upper than Li/Na/K // Lower than Li/ Na


Question No. Rubric Score1 (e)(ii) Able to arrange the metals in ascending order based on

their reactivity.

Sample answer:

Lithium, Sodium, Potassium, X // Li, Na, K, X

3

Able to arrange any three of the metals in ascending order based on their reactivity.

Sample answer:

X, Li, Na, K // Li, K, Na, X // K, Li, Na, X // Na, Li, K, X // Na, K, Li, X // Li, X, Na, K

2

Able to arrange any two of the metals in ascending order based on their reactivity or arrange in descendi ng order .

Sample answer:

X, K, Li, Na // X, Li, Na , K // K, X, Na, LiK, X, Na, Li // X, Na, K, Li // Na, K, Li ,X

X, K, Na, Li //

1


Question No. Rubric Score1 (f) Able to state the relationship between the mass of sodium

and the time taken for the metal to burn completely in oxygen gas.

3


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- the higher the mass / the bigger the size- the longer the time taken- burn completely

Sample answer:

The higher the mass of metals, the longer the time taken to burn completely. //

The bigger the size of metals, the longer the time taken to burn completely.

Able to state the relationship between the mass of sodiumand the time taken for the metal to burn completely in oxygen gas.

Sample answer:

The higher the mass of metals the longer the time taken. //

More mass more time to burn completely //

2

Able to state the relationship between the mass of sodiumand the time taken for the metal to burn completely in oxygen gas.

Sample answer:

Bigger mass burns longer. //

The metals needs longer time //

More mass more time to burn.

1


Question No. Rubric Score1 (g) Able to record all the readings with one decimal place

accurately.

Sample answer:3


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10.1 , 10.6, 10.9

Able to record any two readings with one decimal placeaccurately.

Sample answer:

10.1, 10.6, 10.8 // 10.1 , 10.5, 10.9 // 10.0, 10.6, 10.9

2

Able to record at least one reading with one decimal placeaccurately.

Sample answer:

10.1 // 10.6 // 10.9

1


Question No. Rubric Score1 (h) Able to state observations for blue and red litmus paper

correctly.

Sample answer:

Solutions Red litmus paper Blue litmus paper Gas Jar I Turns blue No changeGas Jar II Turns blue No changeGas Jar III Turns blue No change

3


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Able to state any one of the litmus paper observationscorrectly.

Sample answer:

Solutions Red litmus paper Blue litmus paper Gas Jar I Turns blue Turns redGas Jar II Turns blue Turns redGas Jar III Turns blue Turns red

//Solutions Red litmus paper Blue litmus paper

Gas Jar I Turns red No changeGas Jar II Turns red No change

Gas Jar III Turns red No change

2

Able to give an idea on litmus paper observations.

Sample answer:

Solutions Red litmus paper Blue litmus paper Gas Jar I No change Turns blueGas Jar II No change Turns blueGas Jar III No change Turns blue

1


Question No. Rubric Score1 (i) Able to write the two balanced chemical equations for the

reaction accurately.

Sample answer :

i. 4Na + O 2 2Na2O and

ii. Na 2O + H2O 2NaOH

Notes: Sodium can be replaced with any alkali metals fromTable 1.

3


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Able to write two chemical equations with correct chemical formulae but not balanced // Any one of the two balanced chemical equations for the reaction accurately.

Sample answer:

i. Na + O 2 Na2O and

ii. Na 2O + H2O NaOH //

i. 4Na + O 2 2Na 2O //

ii. Na 2O + H2O 2NaOH

2

Able to give at least one chemical formulae of the substances correct // Able to write any one of the twochemical equations with correct chemical formulae but not balanced .

Sample answer:

i. Na // O 2 // Na2O and

ii. Na 2O // H2O // NaOH

i. Na + O 2 Na2O //

ii. Na 2O + H2O NaOH

1


Question No. Rubric Score1 (j) Able to classify all alkaline solutions into strong alkali and

one weak alkali correctly.

Sample answer:

Strong alkali : Sodium hydroxide / NaOH,Potassium hydroxide / KOH

3


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Weak alkali : Ammonia solution/ NH 3Calcium hydroxide / Ca(OH) 2

Able to classify any two of strong alkali and one weak alkalicorrectly.

Sample answer:

Strong alkali : Sodium hydroxide / NaOH,Potassium hydroxide / KOH

Weak alkali : Ammonia solution / NH 3

2

Able to classify any one of strong alkali and weak alkalicorrectly.

Sample answer:

Strong alkali : Sodium hydroxide / NaOH //Potassium hydroxide / KOH //Calcium hydroxide / Ca(OH) 2 //

Weak alkali : Ammonia solution / NH 3

1


2010 Terengganu P3ES2

Question Rubric Score

26 (a)

Able to state the two observation correctly

Sample answer:1. Burns very rapidly // burns vigorously2. produces white fumes

3

Able to state any one answer correctly 2Able to give an idea of the observation

Sample answer:Burns // white solid // produces solid // burns rapidly


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No response give // wrong response


(b)

Able to state the relationship correctlySample answer:Going down the Group 1 element, the reactivity towards oxygenincrease.

3

Able to state the relationship less accuratelySample answer:Different type of Group 1 element, different reactivity towardsoxygen.

2

Able to give an idea of relationshipSample answer:Position of Group 1 element affected the reactivity.

1



(c)

Able to give the inference correctlySample answer:Alkaline solution produced.

3

Able to give the inference less accuratelySample answer:

Lithium hydroxide formed

2

Able to give an idea of the inferenceSample answer:Alkali metal

1



(d)

Able to predict the position of X metal in the periodic table

correctlySample answer:Between potassium and lithium // below lithium and above potassium

3

Able to predict the position of X metal in the periodic table lessaccuratelySample answer:Below lithium // above potassium

2

Able to state an idea of the position of X metal in the periodictable.Sample answer:

1


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Group 1 element No response give // wrong response 0


(e)

Able to classify all the ions correctlySample answer:

Cation AnionLithium ion // Li +

Hydrogen ion // H +Hydroxide ion // OH -

3

Able to classify any two ions correctly 2Able to classify one ion correctly or give opposite heading 1

No response give // wrong response 0


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2010 SBP P3ESQ No. Rubric / Sample answers Score

271(a)

Able to state hyphotesis accuratelySample answer : metal which is lower down in group 1 is more reactivetowards oxygen // X is more reactive than sodium and lithium towardsoxygen

3

Able to state the inference less accuratelySample answer :Reactivity towards oxygen increases when going down group 1// sodium ismore reactive than lithium towards oxygen

2

Able to state the idea of inferenceSample answer : metal can react with oxygen

1


1(b) Able to record the observation correctlySample answer : metal X burns more vigourously and produces white fumes 3

Able to record observation less correctlySample answer : metal X burns vigourously and produces white fumes 2

Able to state an idea of observationSample answer : metal X burns in oxygen //produces white fumes 1


1(c) Able to construct a table with the following aspect correctly1. title2. observationsample answer :

Set observationI Lithium burns slowly and

produces white fumesII Sodium burns vigourously and

produces white fumesIII Metal X burns burns vigourously

and produces white fumes

3

Able to construct a table less accuratelySet observation

I Lithium burns slowly and produces white fumes

II Sodium burns vigourously and produces white fumes

III Metal X burns burns vigourouslyand produces white fumes

2


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