Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 PERIODIC TABLE OF ELEMENTS PAPER STRUCTURE No. Rubric Marks (a) (i) Group Period (ii) F (b) (i) E L (ii) Soluble in water// high melting point/ boiling point// conducts electricity in molten or aqueous solution (c) (i) E (ii) The nuclei attraction towards the valence electron is weaker in E. Thus it is easier for E to lose/ release an electron to form a positively charged ion. (d) (i) A//C (ii) Covalent bond Total marks 0 (a) (i) T (ii) Q (iii) S (b) Q, P, T, S and R (c).8. (d) T - (e) Both have the same number of shells of electrons (f) Red litmus paper turns blue (g) Transition elements Total marks 9 Chemistry Perfect Score Module Form 4 00 Marking Scheme Set 0
Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 (a) (i) D + (ii) B - (b) (i) 8 (ii).8.8 (c) G (d) (i) DE r: ED, chemical equation (ii) + - - (iii) Ion D + Ion E -. [All electrons and number of shells filled with electron correct]. [Nucleus of atom labeled and charges of ion shown correctly] In aqueous solution//molten state Ions can move freely//free to move Total marks 0 PAPER - ESEI 4 (a) (i) Electron arrangement:.8.7 Element: Chlorine (ii) NaOH + Cl NaCl + NaOCl + H O Correct reactant Correct product Balanced equation (b) The valence shell of electrons in diagram 4. is nearer to the nucleus compared to diagram 4. Chemistry Perfect Score Module Form 4 00 Marking Scheme Set
Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 Diagram 4. has shells and diagram 4. has shells. The nuclei attraction in diagram 4. is stronger than diagram 4.. Diagram 4. is more electronegative than diagram 4. because it is easier to receive electron. Diagram 4. is more electronegative and more reactive than diagram 4.. // Atomic size / distance between nucleus and valence electrons. Nuclei attraction between nucleus and valence electrons Tendency to receive electrons to form negative ion Atom diagram 4. Atom diagram 4. Smaller / nearer Bigger / farther Stronger Easier Weaker Difficult Reactivity More Less (c) Less reactive (d) (i). all connection of the apparatus are tight to avoid the leakage og gas.. carry out the experiment in fume chamber.. pour the hydrochloric acid carefully to avoid it from spilling. (ii) In Part A; Iron wool reacts with chlorine gas to form solid iron (III) chloride. Cl + Fe FeCl In Part H; Sodium chloride, sodium chlorate (I) and water are formed from the reaction between excess chlorine and sodium hydroxide solution. NaOH + Cl NaCl + NaOCl + H O + + + Total marks 0 Chemistry Perfect Score Module Form 4 00 Marking Scheme Set
Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 PAPER - STRUCTURE 5(a) To state the variables Explanation Manipulated variable : metals of Group elements // sodium, lithium, potassium. Responding variable: the reactivity of the reaction with water // the speed of movement on the water surface Constant variable: size/mass of metals. Volume of water Explanation Repeat the experiment by using the metals of sodium, lithium and potassium To observe how fast the metals move on the surface of water. Use the metal granules with the same size. 6 [Able to state the relationship between the manipulated variable and the responding variable correctly] The reactivity of Group elements increases going down the group. (c) [Able to arrange correctly the reactivity series of the metals according to descending order] potassium, sodium, lithium (d) The metal that reacts more vigorously with water is a more reactive metal. (e) [Able to classify the ions correctly] Positive ion/ cation : sodium ion/ Na +, hydrogen ion/ H + Negative ion/anion : hydroxide ion/ OH - Chemistry Perfect Score Module Form 4 00 Marking Scheme Set
Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 PAPER - ESEI 6(a) [ Able to state the problem statement clearly and accurately] How does the reactivity of Group elements change when they react with water? [Able to state the problem statement slightly inaccurate] To study the reactivity of Group elements. [Able to provide an idea of a problem statement] The reactivity of Group elements. (b) Stating variables [Able to state all the corresponding variables accurately] Manipulated variable : Type of Group metals Responding variable : Reactivity of reaction Fixed variables : Water, size of metals [Able to state two corresponding variables accurately] [Able to state any one corresponding variable correctly] (c) [Able to list all materials and apparatus correctly] Materials A small piece of lithium, sodium, potassium and water Apparatus [Suitable container], forceps, Knife, filter paper [Able to list the basic materials and apparatus required] A small piece of lithium, sodium and potassium, water Apparatus [Suitable container], forceps [Able to provide an idea of materials and apparatus used] Group metals, water, forceps Chemistry Perfect Score Module Form 4 00 Marking Scheme Set 4
Set Marking Scheme :Periodic Table of Elements & Chemical Bonds 00 [Able to state all experimental steps correctly]. Cut a small piece of lithium using a knife and forceps.. Dry the oil on the surface of the lithium with filter paper.. Place the lithium slowly onto the water surface in a trough 4. Observe the reactivity of the reaction 5. Repeat steps to 4 using sodium and potassium to replace lithium [Able to provide steps correctly to carry out the experiment] Steps,4 and 5 [Able to provide minimum of steps correctly to carry out the experiment] Steps and 4 [Able to construct a table correctly containing the following elements] Metals Observations Lithium Sodium Potassium [Able to construct a tabulation of data containing the following elements] Metals Observation [An idea of a tabulation of data ] - Minimum of rows and columns Chemistry Perfect Score Module Form 4 00 Marking Scheme Set 5